The goal of most maps is to take your force of marines and destroy all the alien hives, capturing the points they're located on.

Build Points (BP) are the resource you use to buy upgrades, equip your marines, and build structures. You start with a small amount of BP, and can gain more by:
- Towing BP crates (purple crates) back to a base you control (3 BP)
- Capturing an alien hive (6 BP)

BP can be spent to get more marines (via the button in the upper right corner), or by using the Training, Research, and Armoury menus in the lower left corner.

A difference between Infested Planet and other similar games is that you can always undo your actions in order to get the spent BP back. Marines can be dismissed (again via the button in the upper right corner), structures that you built can be destroyed (by selecting them and pressing D), and marines that have been given different weapons can be turned back into Riflemen via the Training menu.

This is crucial to understand because it means that your approach and strategy can change as necessary throughout the game.

As you capture alien hives, the aliens will mutate, making them more powerful.

Outside of specific scenarios in the campaign, mutations are always a result of capturing hives. Each mutation will have a different effect on the game, and some of them can be very, very nasty. See the Mutations section for specifics.

In the campaign, after completing a map, you will receive some money. Money can be spent at the Store between missions.

The Store offers two types of advantages:
- Upgrades unlock something
- Buffs are advantages you keep until you win a map

The Store receives more and more options as you progress through the campaign maps.

You will eventually want all the upgrades -- these unlock all of the options in the Training, Research, and Armoury menus, as well as giving you Bunkers. Once you buy an upgrade, it is removed from the Store.

Buffs are minor advantages -- either having extra marines, or having a marine start as something other than a Rifleman. They are essentially bonus BP spent in certain ways. They will "stay bought" until you win a map, at which point you will need to buy them again. You never need to buy a buff -- all the maps and achievements are possible without them -- but they give an advantage if you are having difficulty.

You can replay maps over and over to get money. If you quit a map without winning, you will also get a partial amount of money based on the number of aliens killed / hives captured.

Each of your marines has a health bar. When the bar is fully red, that marine is in perfect health. As the marine takes damage, the bar will slowly empty. When the bar is fully empty, the marine dies.

When a marine dies, the bar turns gray, and will begin to slowly refill. When it is full, the marine will respawn -- usually, but not always, at the base closest to where they died.

Marines can also be poisoned via the aliens' ranged attacks. Poison damage does not take effect immediately -- instead, some of the marine's life bar will turn green. Over time, the green portion will be removed (one tick every 3 seconds or so). If a marine's entire life bar is green, that marine will eventually die if they do not receive healing.

Poisoned marines will also move slower than normal marines.

Marines can be healed in three ways:
- Being near a bunker (each bunker can heal one marine at a time)
- Being near a medical pod (each medical pod can heal one marine at a time)
- The Life Support upgrade (will constantly heal all marines)

In the upper left hand corner is an ammo bar. This ammo is used for Rockets, mortar firing, and for some upgrades (Chopper Strike, Reinforcements, and Engineering). In the Trickster's Arsenal DLC, this is also used for the ability menu.

Rockets can be fired by any marine at any structure, and some enemies (clones, guardians). Rockets do a large amount of damage and have an explosive splash effect. They are very useful for speedily taking down enemy structures, as long as you have the ammo.

Your ammo will slowly regenerate over time. In addition, there may be ammo crates (yellow crate) throughout the map. Marines do not tow ammo crates like they do BP crates or medical pods; instead, if a marine "uses" the crate (by being selected and right-clicking on the crate) you will immediately regain 2 ammo per "use". This will happen repeatedly until your ammo bar is full. Each ammo crate contains 20 ammo; when all of that has been taken, it will disappear.

If you have the Ammo Supply upgrade, miniature ammo crates will also appear at points. These are picked up automatically by a marine moving nearby, and will give 2 ammo before disappearing.

This DLC adds the Ability menu, Hunt missions in the campaign, mutators in the Abyss/Terminus maps, and the Ironman weekly challenge.

The Ability menu, as well as mutators, are available to everyone, even those who do not have the DLC, in the weekly challenges. This ensures the Bronze/Silver/Gold leaderboards are fair.

You can buy additional marines using the buttons in the upper-right hand corner. The first additional marine costs 4 BP, then 5 BP, then 6 BP, etc. You can sell marines to get BP back -- you can even sell two of your starting marines (for 3 BP and 2 BP, respectively).

You can change a marine's weapon loadout from the training menu.

The costs given here are to turn a rifleman into the specified type. But you will never lose BP by changing your marine's loadout -- so if you turn a rifleman into a flamer, that costs 7 BP, but if you then turn the flamer into a shotgunner (normally costing 4), you will receive 3 BP back.

Cost: Free
Riflemen are your basic marines. They are average in all respects, and shoot their rifle in short bursts at the enemy with a small amount of piercing. Their rifles do average damage, but since their weapon has no area of effect, they are quickly overwhelmed by crowds of bugs.

However, riflemen are still useful for towing crates, building buildings, firing rockets, or defense. One rifleman by themselves is not enough to hold off a stream of bugs.

Riflemen benefit tremendously from the Grenades upgrade, allowing them to handle crowds a lot more efficiently than normal. One rifleman with Grenades is capable of holding off a stream of bugs, and maybe even two.

Usage: In general, riflemen should be upgraded to something else as soon as the BP is available.

Cost: 4 BP
Shotgunners share most of the same attributes as riflemen, except that their weapon fires multiple hits in a cone-shaped spread. Shotgunners are excellent at taking on a swarm of bugs.

A shotgunner can essentially hold off an additional stream of bugs over a normal rifleman; a shotgunner can hold off one stream, and one with Grenades can hold off two, and maybe even three, streams.

Usage: In general, use shotgunners only when BP is tight and you can't afford a flamer (such as at the beginning of the map). Shotgunners are better than flamers versus spitters.

Cost: 5 BP
Scouts are the fastest and the weakest marine. They make up for their frailty by traveling around the battlefield invisibly. Scouts become visible if they are towing a pod, or near spitters. Avoid both of these cases, as scouts will go down quickly due to their poor health. A scout who has been detected will turn red.

The scout carries an odd weapon; it can kill clones in one hit, and kill roughly half of the towers on the map in one hit (the other half, scouts will never be able to kill with their weapon, though they can still use rockets).

Usage: Scouts are useful at the beginning of a map, as they can roam undetected and kill towers -- any that they can't kill with their weapon can be taken down with rockets. Change them to some other class, such as flamer, before towing BP crates back to base, however.

Scouts can also be used to get marines into position. This is especially useful with flamers, who have to get very close to have an effect.

If clones are coming towards your marines, quickly change some or all them into scouts, let them headshot the clones, and then change them back. This won't work against clone minigunners -- against those, use snipers instead.

Cost: 6 BP
Officers serve two functions: first, they make all of the marines around them faster. Second, when a hive is destroyed, they will inspire nearby marines, making them invulnerable and firing at three times normal rate for six seconds.

Multiple officers do not increase the effects, but do cause the inspiration to last longer.

Officers do not use a rifle, like riflemen; instead, they fire crowd-control grenades, like those given to everyone by the Grenades upgrade.

Usage: In general, it is faster to change all of your marines to scouts, run to the desired location, and change them back, than it is to use an officer.

The inspiration effect is very useful against hives that are packed close together. If you can get one to fall, the six seconds of invulnerability and increased firing are usually enough to get the second to fall. If your timing is good, you can change a marine to an officer at the last second before a hive is destroyed.

If you do not have Grenades, the officer's grenades can be very useful against swarms of bugs.

Cost: 7 BP
Flamers are faster and better armored than riflemen. Instead of a ranged weapon, they use a close-ranged flamethrower that chews through bugs like nobody's business, killing them in 1-2 hits as well as providing knockback.

Flamer damage ignores enemy shields. Multiple flamers firing on the same target will not increase damage. Spread them out, or order them onto different targets.

Usage: With their high speed and high armor, flamers are best at the front, burning up bugs and drawing fire from the rest of your squad. Don't be afraid to just send them right into the thick of things. A flamer in a chokepoint will be able to take on an infinite number of bugs, even brutes. Flamers are even good at taking out guardians, if they can reach them.

Cost: 8 BP
Snipers are, as the name suggests, long range attackers. Their rate of fire is low, so they are not of use against the bug swarms. However, they will one-shot clones and towers, making them useful at softening up a hive before an attack.

Snipers ignore enemy shields. Note that snipers are completely ineffective against hives themselves.

Usage: Snipers become very useful against some of the ranged mutations, like Impact or Bombardment. Change the marines into snipers, have them target the shooting towers, kill them, and then change back and begin the attack.

Two sniper hits will destroy a fully healed guardian, making snipers one of the best ways of destroying guardians and guardian nests.

Snipers are also useful in shooting spawners while they are still close to their hive to kill them before they can actually spawn a structure.

Cost: 13 BP
A slow moving field of destruction, the minigunner continuously fires streams of piercing rounds, allowing each shot to hit a multitude of enemies. In addition, they have the highest health of any marine, as well as a shield that protects them against some damage.

Their two weaknesses are their slow movement speed and their slow turning speed; a minigunner facing threats from multiple directions is not going to last long.

Usage: Their piercing ammunition makes them great tower and hive killers. Three minigunners can basically walk into any situation and destroy it. When they have nothing to fight, it's faster to make them into scouts to move them to the next location.

Avoid putting minigunners into situations where they have to turn repeatedly. It can be useful to send in other marines to take care of bug streams or the like so that the minigunners won't be distracted.

These are the options underneath the Research menu.

Despite being called "Research", these are actually buildings. If the building is destroyed, the benefit is lost until the building is rebuilt. You can destroy any of your buildings at any point to recover the BP.

Cost: 4 BP
Buildings and structures will build themselves, instead of a marine needing to go to their location to build them, for the cost of 2 ammo. Buildings and structures will also automatically rebuild themselves if destroyed.

Note that if you run out of ammo, you can't build *anything* until you get more; there's no option to have marines build things manually.

Usage: Three main uses:

First, this can be used to build your upgrade buildings in a safe environment. Build Engineering, and then build your Life Support, Grenades, etc in a remote corner of the map, and then destroy Engineering.

Second, this can be used to lay down turrets, mine fields, etc in coordination with an attack. That is, you can lay down minefields close to a hive in the direction your marines are going to arrive from, or you can place turrets around where your marines are going to end up, so that they begin shooting as your marines arrive.

Third, you can use it remotely destroy items -- a turret placed with Engineering next to an infested siege cannon will destroy it. You can then destroy the turret (and Engineering) and begin an attack without worry about taking fire from the cannon.

Cost: 5 BP
Marines will respawn faster, and will be dropped off close to where they died instead of back at a base. When they are dropped off, marines are inspired (as if by an officer) and so are invulnerable and shoot at triple speed for six seconds.

However, each respawn now costs 1.5 ammo. If you don't have the ammo, your marine respawns at a base as normal.

Usage: The intent is to support "Once more into the breach!"-style tactics, where you're sending everything you have into a fight.

If you're going to use Reinforcements, you almost certainly want to also be using Life Support for the minimum-27-seconds lifespan.

However, the game never really requires that. Usually there's a far better way of spending your BP; if your marines are dying enough to be taking advantage of this, you should reconsider your strategy instead.

Cost: 6 BP
Doubles the amount of rocket ammo you can have from 10 to 20, and means that special enemies like clones and guardians will drop ammo as well.

Usage: I use this only if I'm intending to combine it with Chopper Strikes. Otherwise, I don't use rockets enough to care.

If you have the Trickster's Arsenal DLC (or are playing weekly challenges), this becomes a lot more valuable because it lets you spam more Abilities. Clones and guardians no longer drop mini-ammo crates, but this is still incredibly useful, and I prioritize it highly.

Cost: 6 BP
Sends in a helicopter to assault the target. The helicopter will first perform anti-infantry missile strikes, and will then shoot anti-building miniguns.

Chopper strikes cost 10 ammo, but this will decrease by 1 every 5 (or so) seconds until it is free. If you have full ammo, you can make two simultaneous strikes (the free one, and one costing 10). If you have Ammo Supply and full ammo, you can make three simultaneous strikes (the free one, and two costing 10 each).

Towers can be destroyed in one strike; bulwarks can be destroyed in three. In general, three strikes will not destroy a hive, but will leave it at a quarter to a half health, with all towers destroyed. Guardian Nests, notably, are not destroyed with three strikes.

Usage: The first usage is to destroy threats around the map, such as the towers that spawn around BP crates, bulwarks, or the like.

The second usage is to soften up a hive before attacking it. In the case of three hives next to each other with a lot of shooter towers, it can be very helpful to use chopper strikes to destroy the towers around one hive, then immediately march in and destroy it, using an officer's inspiration to help destroy the second and third hive.

Destroying and rebuilding the Chopper Strike does not reset the ammo cost. The ammo cost will not decrease while the Chopper Strike building is destroyed.

Cost: 6 BP
Two effects:

The first is that all of your marines will heal, as if they were at a bunker. Tremendously useful in keeping marines alive.

The second effect is that your marines are guaranteed to live for 27 seconds after spawning.

Usage: Life Support is very useful, and I will get it on almost every map, although usually not until after I've captured the first hive. The healing effect is great and really works to keep your marines alive.

Cost: 6 BP
Robotics gives your bunkers a shield and a mini-turret, allowing them to last longer. The turret fires slower than, and has a shorter range than, a regular turret, but it is enough to take care of a stream of bugs.

Usage: Not particularly useful. If you only need to defend one bunker or two bunks, minefields usually do it better. So this is only really useful if you need to protect three or more bunkers you can't otherwise defend. That's a very rare occurrence.

I will sometimes buy this for the convenience factor, but it's still an inefficient buy.

Cost: 8 BP
Causes all of your marines to periodically (every few seconds) toss out a grenade that destroys bugs in an area-of-effect blast.

Has the negative side effect that your marines can no longer fire rockets ('G' key).

Usage: This used to be the is the first upgrade I went for, every time. Now that it removes rockets entirely, it's no longer an insta-buy.

Grenades is a massive increase in the crowd control of your marines, at the cost of the anti-building rockets. Five riflemen going up against a hive with ten spawn towers will never take it -- the bugs generate faster than the riflemen will fire, so that they never hurt the hive; five riflemen with grenades going up against the same hive will take it in less than half a minute.

If you are not planning on using rockets, or have other anti-building measures (snipers, Chopper Strikes), then Grenades is still a very good buy. You can always use Grenades to get to the buildings, then destroy Grenades and fire rockets at the buildings, as well.

These buildings are available under the "Armoury" menu. Unlike the Research buildings, which have global effects, these buildings only have an effect in their immediate area.

Again, they can be destroyed at any time to recover their BP.

Cost: 3 BP
Creates a small minefield that will cause damage to enemies that enter into it. Does not damage structures at all.

Despite appearances, it will never run out of mines. Minefields can never be attacked by the bugs and will never be destroyed except by you.

Usage: Useful for defense; it's the cheapest way of stopping a bug stream, if there's an appropriate chokepoint to place it.

Mines can be placed offensively either via scouts, or with Engineering. You can use this to place minefields right in front of a hive you're about to attack, which will help thin out the bugs and allow your marines to focus on the towers and the hives.

Cost: 4 BP
Launches rockets capable of taking out crowds of bugs (similar to the Grenades upgrade) or damaging towers / hives. Shots against crowds are free; shots against buildings cost 1 ammo.

The mortar has a minimum range inside of which it can't fire; however, it can fire through walls.

Usage: The mortar is not a good choice because of its ammo consumption. It will prioritize buildings, if there are any, so it will cost you ammo if it is capable of doing so, but its damage output is so low that it will never destroy a hive. The end result is that you're wasting ammo and BP.

Mortars can make effective crowd control devices if you can position them correctly (not able to target any buildings).

Cost: 4 BP
If a marine dies within the area of a teleporter, you will receive an AI-controlled marine at the teleporter who will last roughly 30 seconds. This will cost 1 ammo.

The AI marine will be the same class as the marine that died.

Usage: The marine AI isn't great, and I'd rather just have another marine. You can make use of this to suicide your marines, have the AI marines attack a hive, and then have your respawned marines attack the hive, but you're only going to get twenty seconds or so out of it. Very difficult to make use of this offensively, as they appear at the teleporter, and if the teleporter is anywhere near the front it will probably be destroyed.

Cost: 5 BP
A crate that can be towed (like a BP crate). It will heal one marine within its radius at a time (not necessarily the one towing it.

The healing is not cumulative with bunkers, or the Life Support upgrade.

Usage: Though its range is large, it only heals one at a time, usually making it insufficient. Only really useful if you can't build Life Support for some reason -- otherwise, just get Life Support.

Cost: 6 BP
Generates a shield that absorbs some of the damage your marines and buildings in it's area of effect would normally be taking. Notably doesn't prevent poison damage.

Usage: In most cases, I would simply rather have more offense than defense -- even another rifleman over a shield.

This can be used offensively (build it near a hive you're about to attack), but it takes awhile to build and awhile to generate the shield, so it is very hard to combo with. I do not use shield generators much at all.

Proves slightly more useful in Survival/Horde maps, which are more defense focused.

Cost: 7 BP
The turret shoots very much like the minigunner, but lacks in mobility.

Usage: The turret is usually overkill on defense, since the same job can usually be done by a rifleman or minefield for cheaper.

On offense, the turret can be very effective in groups of two or more (one turret by itself tends to be distracted too much by bugs). The only problem is that a turret offense tends to take longer and be more fragile than a marine offense -- marines can take far more hits, especially with Life Support, and the turrets need to be set up and moved manually, which takes time. Engineering speeds it up tremendously.

Cost: 16 BP
A turret with a huge radius, capable of wiping entire hordes off of the map.

Not capable, it should be noted, of destroying buildings.

Usage: Much like the shield emitter, simply too expensive for what it does. In terms of crowd control, I'd rather place five mine fields than one siege cannon. The siege cannon can really only play a support role, destroying enemies and damaging buildings up to 50% while your marines or turrets do the rest of the work. However, for the cost of it in a support role, it'd be better to have Ammo Supply and Chopper Strikes (and 3 BP left over) because those you can direct and destroy buildings with.

Abilities are added in the Trickster's Arsenal DLC.

However, to keep the leaderboards balanced for everyone, the Ability menu is present in all weekly challenges, even for those who do not own the DLC.

Unlike research, armoury, and training, abilities run off of ammo, not BP. Ammo crates and Ammo Supply will both allow you to field more abilities than normal.

Cost: 1 Ammo
Select this and place a beacon. Your marines will respawn at the base closest to this beacon, and auto-attack-move to it. They'll move faster (as if near an officer) for five seconds after spawning.

Usage: Useful if you're throwing your marines into the breach. Otherwise, not that useful. Note that using this does mean that marines who die on defense will no longer respawn at the base they were defending.

Cost: 2 Ammo per marine
All selected marines are teleported to the targeted area. Any crates towed by the marines will not be teleported.

Usage: Words cannot do justice to how incredibly broken...I mean, useful this power is. Burrowing hive pop up behind your lines? Teleport a flamer to deal with it. Main squad went down one path to kill some hives and will now take twenty seconds to get back to the action? Teleport 'em. Need to take out that infested siege cannon before your assault? Teleport. Want to build buildings in some far off corner? Teleport. Overwhelmed and your marines are going to die? Teleport.

Teleport teleport teleport. This ability is so fantastically useful.

Cost: 4 Ammo
Targets a large group, about the same size as a Chopper Strike. Proceeds to lay waste to all enemies, but not enemy structures, within the targeted area.

Note that a marine must carry out the bombing -- a lot like shooting a rocket. This has a really long range (equivalent to a sniper's), but still requires line of sight. If you try to target an area all the way across the map, expect your marine to walk to their almost certain death.

Usage: This is an expensive, but thorough, way of getting rid of a large number of enemies. It is really good at disrupting spitter hordes, or removing all bugs from around a hive as your marines move in.

The other thing it is really good at is killing spawners. With it's long range, it is a much cheaper alternative to snipers for removing a spawner while it is still close to the hive it came from.

Cost: 4 Ammo
Targets a small group of marines. All marines targeted by this immediately receive back 10% of their health, and are shielded from some damage for 15 seconds.

Usage: Spectacular for keeping poisoned marines alive, or when you just need to squeeze three more seconds out of your marines. Counters the downside of Overdose, to some extent. Invaluable during Iron Man missions.

Cost: 6 Ammo
Targets a small group of marines. For eight seconds, they will be inspired (as if by an officer after a hive is defeated): they'll fire 200% faster, and can't die. However, they will lose 35% of their maximum health.

Usage: Chances are very high after using Overdoes that your marines will die -- the inspiration does not keep them from losing damage to poison, so if they are taking any poison damage at all they will likely die due to poison immediately upon the inspiration ending. Steel Curtain can ameliorate this to some extent.

In general, I do not like Overdose, and prefer to use Stasis Field if there's something I am having difficulty handling.

Cost: 6 Ammo
Targets a small group. Any enemies or enemy structures in the targeted area will become frozen for 25 seconds. Frozen enemies will neither move, attack, nor spawn new enemies, but likewise in turn can't be damaged.

Frozen enemies are signified by glowing green; however, note that there is no countdown or warning as to when they will unfreeze.

As with Cluster Bomb, a marine must carry out this power. If you try to stasis something too far away, the marine will walk there to do it.

Usage: This is the panic button. If things are too bad or can't be contained, stasis them and then rearrange to deal with it. If clone minigunners are coming at your base defended by one rifleman, you can stasis them and get better defenders there. A burrowing hive or a spawner can be stasis'ed. A guardian nest, mimic nest, or bulwark nearby a hive can be stasis'ed while the hive is destroyed. Etc. If two hives are close together, one can be stasis'ed while the other is destroyed.

In Hunt or Ironman missions, stasis is a great ability to use against the crawlers.

Note that the stasis target is not large enough to affect a hive and all of its towers -- you'll get, at best, half of a hive's towers in this way.

Cost: 9 Ammo
Brings in four AI-controlled riflemen at the selected target. They'll last for 30 seconds, or until they are killed.

Usage: An expensive power. This is usually only useful in the beginning of the game, when BP is scarce. Even then, it is really only useful as a meat shield -- drop in the AI riflemen, let spitter towers / guardians / whatever attack them, move in your troops. Because they are AI controlled, their targeting priorities are probably not going to be the same as yours, and because they are riflemen, they're not going to accomplish that much.

They can also be used as an expensive emergency defense, but if you have any marines at all in the area, Stasis Field is probably better.

Slow, stupid, crawling aliens. You will slaughter thousands of these, and in most cases won't even break a sweat doing so.

Bugs spawn from hives and spawn towers.

The bugs' threat is that there can be a lot of them. Riflemen, officers, scouts, and snipers, can be overwhelmed by numbers. Minigunners can be overwhelmed if the bugs are coming from multiple directions due to their slow turning speed. Shotgunners and flamers will basically never be overwhelmed. The Grenades upgrade marines will help tremendously against bugs.

The other bug threat is that they can provide too many targets -- this is mostly a problem with turrets and minigunners, where they can spend time shooting bugs instead of useful things like towers.

Counter: Flamers, shotgunners, minefields, Grenades, etc.

Larger bugs that, when shot, calcify and will begin to regenerate. If they're left alone, they will heal and keep going. Otherwise, they take 3-4 hits to destroy.

Brutes spawn from the Brute Guard or Brute Spawn mutations, and occasionally from protohives.

They can, for the most part, be treated more like bugs, except that they will overwhelm easier because they take multiple hits. Riflemen are certain to be overwhelmed, even with Grenades.

Counter: As per bugs, just more so. Flamers, shotgunners, minefields, etc.

Fast bugs that charge at you and explode in a cloud of poison.

Enraged spawn from the Enraged Guard or Enraged Spawn mutations, or from protohives.

Counter: The best counter is to be in a group, along with some form of healing. No single marine has the rate of fire to keep from taking some damage.

Bugs that shoot poison. Individually, they are weak; the problem is that there can be a lot of them.

Spitters spawn from the Spitter Guard or Spitter Spawn mutations, and occasionally from protohives.

Spitters bring problems: one, that they can focus fire on a single target, and two, they can fire out of the range of flamers.

Finally, spitters can detect scouts, causing them to lose their invisibility. This usually results in dead scouts.

Counter: Shotgunners, minefields, and Grenades. Flamers can work but will need to be micromanaged to make sure they're always in range.

Guardians are bugs that shoot poison, like spitters, but are stronger, move very quickly, will retreat to heal, and most importantly, swarm.

Guardians spawn from Guardian nests, or from hives with the Guardian mutation. There will either be 7 of them (around a nest) or 12 (around a hive).

Guardians have a detection range; when a guardian detects a marine, that guardian and all other nearby guardians will move to attack. It is not possible to kite a single guardian; you'll always get a group of them. Even if you retreat, the guardians will pursue until either each one has been forced to retreat, or everything in their detection range is dead.

All guardians near nests or hives will regenerate, like your marines do when near a bunker. When a guardian gets damaged, it will retreat back to its hive or nest to heal. If a guardian is killed but the nest or hive is not killed, it will respawn after a small delay like towers do.

They are, without a doubt, the worst enemy you will face.

Counter: Snipers will kill guardians in two hits, so the best counter is two (or more) snipers. Flamers can kill them, but suffer from their short range -- scouts-that-turn-into-flamers are ideal, but I have also had success using flamer/shotgunner combinations. Finally, three minigunners with some form of healing can take them, but it will take awhile (some of them will be able to retreat and heal).

Placing minefields on the guardian spawnpoints won't destroy the guardians, but will destroy them when they come back to heal.

It is oh-so-critically important that you engage guardians in only one group at a time -- if you fight a group of guardians around one hive and accidentally wander into the detection range of guardians around a second hive, you're probably dead.

Clones are enemy versions of your marines. They are also called mimics.

Clones spawn from the Assassins, Clone Strike, Mimicry, or Necrophage mutations, or from Mimic Nests. Clone Strike will cause a warning beforehand; the other methods will not.

Like your marines, clones can come in different classes which mirror your classes. Note that clone minigunners, like your minigunners, have a shield.

Counter: Scouts and snipers will both one-shot clones. The only exception is clone minigunners -- because of their shield, scouts cannot effectively hurt them, so they require snipers, minefields, or focused fire to take down.

It is often completely sufficient to simply change marines into scouts or snipers when the clones are approaching, and then change them back afterwards.

These creatures move quickly towards your base. When killed, they will disappear, spawning a structure in their place.

Spawners only appear due to a mutation: Bulwarks, Guardian Nest, Mimic Nest, Protohive, or Tower Spawner. The mutation determines what they spawn.

Spawners will always prompt a warning beforehand that notes which hive they will come from, and will be marked with a "Danger" flag when on the move.

Counter: A tower spawner will always spawn towers when it dies, so you need to think about the tower removal instead of stopping the spawn. For the others, if you can kill the spawner while it is close to an enemy structure (like the hive it's spawned from), it will not spawn it's structure.

The easiest ways to do this are to immediately launch two Chopper Strikes at the hive the spawner will spawn at (one will not inflict enough damage), or to have a sniper nearby that you can focus onto the spawner the second it appears. If the spawner gets more than about a hive's width away, it's too late; in addition, remember that this won't work on tower spawners.

Crawlers only appear in the Hunt campaign missions and the Ironman weekly challenge, both of which require the Trickster's Arsenal DLC.

When a hive is destroyed, and at fixed time intervals, a crawler is spawned. It will attempt to run to a randomly chosen place in enemy territory; if it successfully gets there, it will disappear, spawning a hive in its place.

Crawlers drop Barriers behind them, which do a good job of negating almost all damage from the rear.

Counter: Due to the Barriers, the best counter is to be in front of the crawler. Give it a second to see where it is going, then Teleport Jump your squad in front of it, or Stasis Field it and move your marines in front so that it will be running at them.

Rockets can be very handy in taking a crawler down, as long as they are coming from the front, not the back. A squad of five riflemen throwing rockets can take a crawler down, as long as they are attacking the front.

Beyond that, snipers are very good at killing crawlers, again, as long as they are attacking the front.

Enemy bases. In most cases, you win the map by destroying each of these and capturing their point.

A hive will be protected by twelve towers -- either all spawning towers, all spitting towers, or a mostly equal mix of both. Hives may also have infested structures attached to it during map creation. Finally, hives will spawn bugs that will crawl towards your nearest bases.

If a hive is attacked but not destroyed, it will regenerate health and respawn towers and infested structures. This process is fairly quick; hives can't be worn down through attrition.

In most maps, capturing a hive will trigger another mutation.

Counter: Hives, by themselves, cause little danger -- the bugs they generate are usually ignorable. It's the towers and other defenses around them that need to be dealt with.

Minigunners will deal damage quickly to a hive, even one with defensive mutations. Flamers are good for applying continuous damage to a hive, and will also kill respawning towers and the like, but will take longer to destroy the hive than minigunners will.

Rockets can, especially in the beginning, be used to take down a hive faster than normal.

Towers come in two varieties:
- Spawn towers spawn bugs which will crawl towards detected objects
- Spitter towers shoot poison at detected objects

Towers can appear around a hive, in a group of four towers around a BP crate, or spawned by a spawner due to the Bulwarks or Tower Spawner mutations. If you destroy a tower around a hive or bulwark, but do not destroy the hive or bulwark, it will respawn after a small delay; in the other case, if it is destroyed it will never respawn.

Counter: Pretty much anything. Spawn towers are less of a threat than spitter towers, because bugs are simple to kill.

Snipers will one-shot towers from outside their detection radius.

Scouts can one-shot half of the towers on a map. If they can't one-shot it, they won't be able to destroy it with their weapon (but can still use rockets)

Anyone can destroy a tower with a single rocket.

Chopper Strikes can destroy towers.

In general, towers do not have a lot of health, so anything that can apply damage will do fine. For a hive with no mutations, it's perfectly fine to send in a single flamer.

Spawn towers do not significantly benefit from any mutations, but spitter towers can benefit tremendously from Bombardment (increase their range) , Impact (spitter tower hits cause knockback), or Neurotoxins (poison damage slows target). If those pop up, spitter towers may need to be dealt with specifically, usually via sniper or Chopper Strike.

Protohives, despite the name, are nothing like hives; they are more like spawn towers.

Protohives are created on the map when the map is created, or spawned by the Protohives mutation.

Protohives do not have towers, and do not send out bugs to attack. Instead, when you get within a protohive's detection radius (which is rather large), it will begin to flash purple. The flash will steadily increase in frequency until the protohive spits out a swarm of a type of bug: either brutes, enraged, or spitters. A given protohive will only emit that one type of alien.

Unlike hives, protohives do not regenerate without the Regeneration mutation.

Counter: Especially given their lack of regeneration, protohives are more of a nuisance than a threat. Three Chopper Strikes will kill one, but marines do the job just as well.

A guardian nest has seven guardians around it. If a guardian is destroyed but the nest survives, the guardian will be respawned.

Guardian Nests can be created when the map is created, or spawned as a result of the Guardian Nests mutation.

Counter: As per guardians: snipers, or flamers that can be brought into position via scout. Note that Chopper Strikes will not destroy a Guardian Nest.


A mimic nest is a nest surrounded by five mimic eggs. If marines come into the detection range, the eggs will glow purple briefly, and then hatch clones. Mimic eggs will respawn shortly after hatching, or if destroyed, if the nest is not destroyed.

Mimic nests may be created when the map is created, or as a result of the Mimic Nest mutation.

Counter: Snipers and scouts can kill the clones; any amount of damage will kill the nest eventually. Once the eggs are gone (either via hatching or damage) a single flamer flaming the nest will also keep new eggs from spawning and will eventually destroy the nest himself.

Bulwarks are a central, Nest-like building surrounded by towers.

Bulwarks are placed during map creation, or spawned by spawners with the Bulwarks mutation.

If a tower is destroyed, but the Bulwark is not, the tower will be respawned, similar to a hive.

Counter: It's exactly like taking down a hive, but scaled down. Three simultaneous Chopper Strikes will destroy a bulwark.

Alien-controlled versions of your mortars, turrets, siege cannons, medical pods, or shield emitters. They will have a vivid pink background.

Infested structures are created at the start of the map, or via the Infestation mutation when one of your structures is destroyed.

Infested structures created at the start of the map are tied to specific hive. If they are destroyed, but the hive is not destroyed, they will eventually respawn.

Infested medical pods heal towers, hives, or nests around them (but only one at a time). They will never move.

Infested shield emitters generate a shield that absorbs some damage until it is destroyed.

Infested mortars, turrets, and siege cannons will fire at anything in their detection range. Mortars have a minimum range as normal, but do not have any ammo constraints.

Counter: Anything, really. In general, these structures are easily destroyed and don't have much an effect. The one real exception is siege cannons, which have both a tremendous range as well as a slowdown effect.

Snipers and flamers are unaffected by infested shield generators.

For siege cannons, it is often useful to destroy it before assaulting the hive. In that case, you still have many options: two simultaneous Chopper Strikes, a turret placed via scout or Engineering, a scout who then turns into a flamer when next to it, etc. At worst you can just charge it with marines -- it'll take them awhile to get through the shots, but it really is more of annoyance than damage.

In the Trickster's Arsenal DLC, mutators appear at the harder difficulty levels (Abyss and Terminus). Even those without the DLC can still see them in the Silver and Gold weekly challenges.

Mutators are buildings attached to certain hives at the creation of the map. They do nothing. However, when they are destroyed, the aliens gain another mutation -- the icons that float around the mutator will tell you what mutation it will be, or you can mouse-over. If you capture a hive a mutator is attached to, it is automatically destroyed. Destroyed mutators leave a BP crate.

Counter: None. If at all possible try to save hives with these for last, as the mutations are usually strong.

Mutations are advantages given to the aliens.

In most maps, mutations are caused by capturing hives. In some maps in the campaign, there may be other things that cause mutations (such as clones capturing crates in Tension, or the timer in Endgame); those will be specific to only that map.

In the campaign maps and the weekly challenge maps, the mutations are predetermined (Endgame is an exception). In random maps, they are random. Of note is that on the Terminus maps, they are random but are weighted against whatever strategy you are using (using flamers is more likely to get Bombardment, Impact, or Neurotoxins; using turrets is more likely to get Rust or Infestation, etc).

If a mutation says it occurs "periodically", there will be a warning before it occurs, along with a distinctive sound.

Periodically, groups of clones will be spawned at hives -- 3 clones per officer you have. They will move towards the officer and attack him in preference to others.

Hives receive a barrier that protects them from bullets. Flamers and rockets ignore this. Minigunners do not seem hampered by it.

The range of spitter towers increases to that of a sniper's.

Hives will now spawn brutes instead of bugs when your marines are near.

Hives will now spawn brutes to go attack your bases instead of bugs.

Periodically, a hive will emit a spawner that will travel a path to create a bulwark.

Periodically, a hive will spawn in your territory. The initial warning will be vague, and will get more accurate as the spawn approaches.

This is one of the most annoying mutations. You usually need to stop what you're doing to take care of the hive, and time your attacks around it.

After you capture a hive, barriers will be created a long a path between alien hives and your bases. These barriers block your movement and shelter aliens from attacks. They can be destroyed. Use flamers or minigunners.

Towers receive a barrier that protects them from damage.

Periodically, clones of your marines will be generated at a hive. There will be a rough outline of their path. Watch out for minigunners.

Hives can consume their own towers to heal themselves and become invulnerable for a few seconds.

After capturing a hive, alien spawn rate and speed are increased significantly for a short while.

Hives will now spawn enraged instead of bugs when your marines are near.

Hives will now spawn enraged to go attack your bases instead of bugs.

Periodically, a hive will emit a spawner that will travel a path to create a guardian nest.

Towers around hives are replaced with guardians. This mutation is one of the more difficult ones you can experience.

Hives that are hit by an explosion (rockets, grenades, etc) will get a shell around them that resists damage.

Hives with less than a third of their towers intact get a shell around them that resists damage.

Hives that take damage will reply with poisonous spit, like a spitting tower. Seems to have an area-of-effect splash.

Spitter towers now have a large knockback effect. This can hamper flamers tremendously.

When one of your Armoury structures is destroyed by aliens, it is replaced with an infested version. Unlike the ones tied to hives, these will not respawn if destroyed.

Periodically, a hive will emit a spawner that will travel a path to create a mimic nest.

When a hive is destroyed, it will spawn three mimic eggs. If the eggs are not destroyed within a few seconds, they will hatch, generating clones with the classes of nearby marines.

A mimic egg is placed wherever a marine dies. If not destroyed in a few seconds, it spawns a clone.

Poisoned marines move slower. Much slower.

Periodically, a hive will emit a spawner that will travel a path to create a protohive. Instead of emitting bugs, this hive will emit different alien types randomly.

Barriers reflect bullets back at you. This does not seem to do much damage overall.

Hives heal nearby structures faster than normal.

All of your structures take double damage from alien attacks.

Some poison damage is taken instantly, instead of over time.

Hives will now spawn spitters instead of bugs when your marines are near. Keep in mind spitters detect scouts.

Hives will now spawn spitters to go attack your bases instead of bugs. Keep in mind spitters detect scouts.

All hives will slowly deploy mines around themselves. Your marines will take a lot of poison damage setting them off, but can also shoot them. Invisible scouts are apparently unable to shoot them, and will die if they set one off.

Periodically, a hive will emit a spawner that will travel a path to create a mess of towers. Unlike the other spawner mutations, you can never stop these towers from being created. It is usually better to let the spawner get to your area first, to make the cleanup easier.

The opening missions, up to and including Science Station, are relatively straightforward and shouldn't require much in the way of explanation.

Then we get to Night and Day.

The goal is the same -- capture all enemy hives -- but there are two "phases" for the aliens: an aggressive night phase where they attack in large number with mutations, and a passive day phase where they are not aggressive and do not have mutations.

In addition, you cannot let the lab building be destroyed.

Achievements for this level are:
- Night and Day: Beat the map
- Early Dawn: Finish Night and Day in 11 minutes or faster.
- General Stonewall: Finish Night and Day without losing a point

Available training: Riflemen, Shotgunners, Officers, Flamers
Available research: Ammo Supply, Chopper Strike, Life Support
Available armoury: Minefield, Medical Pod, Turrets

Map:


Mutations: These are only present during the night phases. During the day phases the aliens have no mutations.

• Barriers
  
• Counterattack
  
• Hive Spit
  
• Tower Spawner (3 hives captured)
  
• Protohives (5 hives captured)
  
• Carapace (7 hives captured)

During the initial night phase, position your marines at the X's marked on the map. Make them shotgunners. Attacking at this point isn't useful, so just concentrate on defense.

As soon as the night phase ends, make everyone a rifleman again, and send the two southern-most marines towards the group of three hives noted '1'. Build two turrets that will be in range of one and only one hive (so they focus their fire). Make one of them a shotgunner. For your remaining marines, send them south as soon as there are no more bugs headed in their direction.

Use rockets to destroy towers as you are able. If any marine takes too much damage, send him back to a bunker to heal. When the first hive is destroyed, destroy and reposition the turrets so that they are now in range of the second hive. When that one's gone, destroy and reposition so they are in range of the third hive. Meanwhile, with healthy marines, capture the points for the two destroyed hives, and send marines to get the three BP crates in the area. Finally, capture the third hive. Build Life Support.

You should have 1:20 or thereabouts left in the day phase. Destroy the turrets. The next goal is to take out the hive marked as 2 on the map. You have more than enough BP to make everyone a shotgunner, and to build some turrets to help. You should capture it with 20-30 seconds remaining.

Send one shotgunner to the north to build three turrets that barely encompass one of the hives marked '3'. Send one shotgunner too the western base, one shot gunner to the chokepoint to the southeast of the lab, and two shotgunners to the base area north of the lab. Build a turret to the north and south of the lab.

Since you have captured 3+ hives, there will be tower spawner attacks during the night. Hopefully, it occurs near your three turrets hammering on the hive. However, if it doesn't, you should destroy and reposition turrets to destroy the towers. Rockets will also prove helpful here.

Ideally, you destroy the hive with around 1:30 left in the attack. Start leapfrogging your turrets; you can also pull the shotgunner from the western base up north to help.

There will be a second tower spawner attack. Watch for it, and move your turrets to be in its way.

With Counterattack, it will be difficult to take the second northwestern hive, but you should be aiming to do so around the time the night phase ends. Rockets can prove helpful in getting that last necessary bit of damage. If your turrets are taking damage from bugs, have the shotgunners stand around them. Ideally you want the turrets destroying towers and hives, not having to shoot at bugs themselves.

When the second hive at '3' goes down, capture it. You can take the time to destroy the bulwark if you wish -- I didn't bother. Have each man go to a different hive and build two turrets there. Capture as you can. You have 2:30 to capture five hives; it should be no problem at this point, as you are swimming in BP.

If you're a little slower than these times, that's ok. These times are on track to complete the map in ~8 minutes, and you get the achievement if you complete it in 11 minutes, so there is wiggle room. The key pieces are that you have to take four hives in the first passive phase, and you have to take at least one hive in the aggressive phase.

You're tasked with protecting convoys that need to travel safely through the map. You may surmise that this becomes an escort mission. You would be wrong.

Achievements for this level are:
- Preparations: Beat the map
- Champion Courier: Finish Preparations in 10 minutes or faster.

(The achievement used to be to make sure no couriers died. *That* was a tough achievement...)

Available training: Riflemen, Shotgunners, Officers, Flamers
Available research: Ammo Supply, Chopper Strike, Life Support
Available armoury: Minefield, Mortar, Medical Pod, Turrets

Map:


Mutations: Mutations are tracked both by number of hives destroyed, as well as number of couriers that have successfully left the map.

• Counterattack (7 hives captured)
  
• Tower Spawner (10 hives captured)
  
• Carapace (14 hives captured)

• Bombardment (3 couriers successful) (at this point, you also receive a free sniper and a rifleman with a medical pod)
  
• Spore Mines (5 couriers successful)
  
• Impact (6 couriers successful)
  
• Rust (8 couriers successful)
  
• Bulwarks (9 couriers successful)

The thing to note is that the mutations for allowing couriers to be successful are way, way, way worse than the ones for capturing hives. So, the path to the goal for this map is to capture hives without allowing couriers to successfully leave the map.

To start with, build Life Support to the southwest of your base. Take the other four marines and send them to the hive marked as '1' on the map -- make one of them into a shotgunner. Use rockets as necessary to destroy the towers, and take the hive.

Send two marines to grab the two nearby BP crates and bring them back. Build a new marine and station him at the captured hive. Change your shotgunner back into a rifleman, and have the marine at the original base build Chopper Strike.

When the couriers appear, they'll run directly into a hive and stay there until they die. That's what you want.

Move four of your marines (leaving one at the original base and one at the captured one) north towards the hives marked '2'. If you are low on ammo, refill from the ammo crate on the way. When your ammo is full, launch two simultaneous chopper strikes on one of the hives at '2'. When the strike is underway, move your marines in to attack. Focus on the weakened hive until it is taken down, then attack the other. Use rockets as they become available.

(If you have difficulty at this part, after unleashing the chopper strikes you can destroy the Chopper Strike building, and then turn one of your marines into a flamer, which will help. If you do this, you want to rebuild Chopper Strike as soon as possible to minimize waiting.)

Capture the two hives, and tow the three BP crates, and then a fourth BP crate to the right. Create a new marine and station him here as defense.

Wait until you have full ammo and the Chopper Strike cost becomes 0. Make one one of your four attackers a flamer, call two simultaneous chopper strikes on the topmost hive marked '3', and once the strikes are underway, attack.

Pause, destroy Chopper Strike, make one of your marines a flamer, and continue.

Attack the hives marked at '3', focusing on a single one at a time. Some micromanagement of the flamers may be required -- at the very least, one of them attacks towers while the other one flames the hive.

After these hives are all captured, you'll want to regroup at '2'. Pick up the guy you left here on defense, and then sweep through the hives at the top of the map. Note that when you capture the fourth one, the Tower Spawner mutation will become active.

You should be swimming in BP at this point. A tower spawner attack is warned ahead of time; put a turret up at the target, and then, when the towers spawn, have a flamer nearby to take care of them. They should be an annoyance that needs your attention, but not a problem.

Clear the hives in the middle of the map. Order doesn't really matter at this point, but I tend to go counter clockwise through those three. The couriers will be free to make their deliveries now, but it shouldn't matter because there won't be enough time to get the mutations they cause.

Finally, wipe out the two remaining hives in the corner and win due to having captured all hives.

This mission is a lot like Contact: capture all of the hives so that you can attack the giant hive in the middle. The problem here is that all of the hives are protected by guardians.

Achievements:
- The Return: Beat the map

Available training: Riflemen, Shotgunners, Officers, Flamers, Snipers
Available research: Ammo Supply, Chopper Strike, Life Support
Available armoury: Minefield, Mortar, Medical Pod, Turrets

Map:


Mutations: The aliens start with the Guardians mutation. After you capture two hives, they gain the Guardian Nest mutation.

Read up on Guardians in the Enemies section. They're fast, and they swarm. You will not be friends with them. You essentially have two ways of dealing with them at this point:
- Snipers: Preferred
- Turrets: Their range is shorter than snipers, and they have to be built. You can do this, but expect your marines to die more often.

In either case, you will usually want to set up just outside of their detection range (the larger circle, if you hover the mouse over one), and then use some poor marine to attract their attention and move them into the killing field.

Throughout this map you also have bunkers that will spit out AI-controlled marines. They'll die by the dozen, but that's fine. They're a useful distraction for the guardians that will keep them from hounding your own marines too badly. The bunkers are, as near as I can tell, invincible -- do not worry about defending them. They will also heal you if you're nearby, which is nice.

However, you do need to worry about the AI marines attracting the attention of guardians, causing them to move closer and then coming in detection range of your marines. It's really annoying when that happens. To counter it, when positioning marines on defense, especially at the south of the map, place them on the portion of the point away from the center.

Now, that all said:

To start with, note that you can destroy the Reinforcements building to get an extra 5 BP. Make snipers, and have everyone attack the guardian nest at '1'. It should fall relatively easy. Collect the two BP crates in the area.

Make one of your riflemen a shotgunner, and send him to the chokepoint south of the hive at '4' -- you want him to be able to cover the chokepoint and kill bugs, but not attract the attention of the guardians.

With the other four: make three of them snipers, and the fourth a rifleman. Set up your snipers out of the guardians detection radius, and have the rifleman act as bait to lure the guardians into range. Three snipers should deal with the guardians quickly -- change two of the snipers into flamers and attack the hive, leaving the third sniper to kill any guardians that respawn. You should be able to take this hive easily.

At this point you should have 8 BP; I recommend building Life Support.

Take the other hive at '2' the same way. Do not wander into the detection radius of the nest of guardians just to the north.

Upon taking this second hive, the aliens will gain the Guardian Nest mutation. Look for where the spawner is going to come from and go; it is likely going to be through the area your shotgunner is guarding. This will be problematic.

These will occur periodically, so even if you're quick you'll need to deal with 3 or 4 of them. Essentially, you have two options:
1) Use a sniper to kill the spawner close to the spawning hive, and deal with it later when you get to that hive, or
2) Let the spawner leave the detection radius of the spawning hive, then attack it with a flamer and have him roast everything.
I tend to favor the second. A flamer can take a nest by himself, if you have Life Support. A flamer cannot take a nest by himself if he'll be within detection range of the hive.

Meanwhile, leave a rifleman at the '2' area and send everyone else to destroy the nest at '3'. It should not be a problem. Drag the three BP crates back to '2'. Get another rifleman and leave him here, one rifleman just south of each point.

You can destroy the nest just north of '2', or leave it for later.

Send everyone besides those two riflemen to the chokepoint just south of '4', where your shotgunner/sniper/flamer should be. Reorganize everyone into one flamer and as many snipers as you can. Attack the hive at '4', capture it, and then drag the two BP crates just north of it.

Destroy the nest at '5'. Note that you will may attract the attention of a *lot* of guardians this way. Even with 3-4 snipers, they might get overwhelmed. If so, no big deal, wait for them to respawn. The important thing is to destroy the nest.

Now comes '6'. This is the first instance where you must fight more than one group of guardians at the same time, so be careful. The easiest way to do this is one flamer in front, and as many snipers as possible behind him. Use your flamer to get just inside the detection radius of the first group of guardians, and let the snipers kill them as they attack. Then do the same for the second group of guardians. Once both groups are dead, have two flamers, one attacking each hive, and the snipers standing around to kill any guardians that respawn.

When both hives are captured, get the two BP crates to the southeast.

Finally, you have '7'. This will be at least three groups of guardians, and possibly more depending upon guardian nests. I recommend making as many snipers as possible, and repeating what you did for '6': move into the detection range of one group at a time, and kill it. When most of the guardians are dead, make two flamers to kill the hives.

Upon capturing the last hive, the general will appear -- an invincible AI-controlled minigunner. Kill any remaining nests, and then wander over and kill the main hive. Unlike in Contact, there will be no attacks from the main hive.

Memento Mori is set up so that you must defend against waves of aliens that progress towards the southernmost part of the map, trying to hold out until rescued.

Achievements:
- Memento Mori: Beat the map
- Thou Shalt Not Pass: Finish Memento Mori while holding more than 1 point.

Available training: Riflemen, Shotgunners, Officers, Flamers, Snipers
Available research: Reinforcements, Ammo Supply, Grenades, Chopper Strike, Life Support
Available armoury: Minefield, Mortar, Medical Pod, Turrets, Shield Emitter

Map:


Mutations:
Oh, god. This map has all of the worst mutations, pretty much at once. To start with, they have Guardians, Rust, Guardian Nest, Protohives, and Tower Spawner.

When the attacks start, they gain Spitter Spawn and Counterattack.

Finally, when you get to two minutes remaining, they will also get Carapace, Hive Spit, and Spitter Guard.

In addition to all of that, the aliens move faster and spawn much faster than normal. In particular, the spawners from the Guardian Nest, Protohives, and Tower Spawner mutations seem to come close to non-stop, rather than having the few minutes between attacks like normal.

You do not capture hives on this map -- instead, every time you destroy a hive, it leaves a BP crate. In addition, starting with the first point you lose and every two points thereafter, choppers will drop two BP crates. These are the only ways to gain BP on this level.

At the start of the attack, and every two and a half minutes thereafter, hives will respawn on the map, as follows:
13:00 minutes (attack start): Four hives in the northern area, and a hive at '1'
10:30 minutes: As above
8:00 minutes: As above, and a hive at '2'
5:30 minutes: As above, and a hive at '3'
3:00 minutes: As above, and a hive at '4'
0:30 minutes: As above, and a hive at '5'

It is these hive spawns, more than anything else, that require you to constantly fall back. Even if you set up the perfect perimeter against the northern area, you will have problems at 5:30 minutes remaining when three hives spawn behind you, with guardians, spitters, generating protohives and tower spawns, etc.

Here are two approaches to the map: the way it's intended to be played, and the utterly cheap way of winning.

When your marines land, immediately move them to the area at '1' where a hive will spawn. You will want to destroy it quickly; I build Grenades, make one marine a flamer, and make two others shotgunners. You may also try Chopper Strike. As soon as it is dead, grab the BP crate and tow it to one of the southern bases.

Pull all of your marines back -- you *want* the northernmost point to fall. Reconfigure your team as so for your 27 BP:
- Grenades (8 BP)
- Chopper Strike (6 BP)
- Ammo Supply (6 BP)
- Flamer (7 BP)

As soon as the point is captured (you see the "Point Lost" message), hit it with a chopper strike -- if there are already towers from a tower spawn around, hit them with two. Move your marines in. Your goal is to destroy the hive, get the BP crate (easiest by recapturing the spot), and get the two BP crates that will be dropped to the southwest for losing your first point. This is not an easy thing to do, especially with the spitters. You may find it easiest to destroy the Ammo Supply after launching the chopper strikes in order to have a second flamer, or to make shotgunners instead. You do not need to live, just to get those BP crates.

At 10:30 remaining, the hive at 1 will respawn. You want to destroy it and get its BP crate again. If at all possible, you can try to let the aliens retake the northernmost point so that you can destroy it and take it back, but it's very difficult to do with the amount of spawners.

Once you've destroyed hive 1 the second time, fall back to the area around '2'. Let the aliens capture all three northern points -- this will generate another 2 BP crate drop in the '2' area, which you should grab. Retake any hives if you think you can, but it is not easy. Use Chopper Strikes to clear towers from the tower spawner. If your buildings get destroyed, just rebuild them.

At the 8:00 remaining mark, '2' will spawn a hive. Destroy it, take BP crate, fall back to '3'. At this point you should have ~45 BP in total. Refill your ammo on the crates and use Chopper Strike with liberal abandon. It is easiest to hole up at the base to the south of '3' to get aliens from both chokepoints.

At 5:30, '3' will spawn, should be destroyed, and you should fall back to '4'. Buildings should be destroyed and rebuilt at the southmost part of the map. You should definitely be using Grenades, Life Support, Reinforcements, and Chopper Strikes, and you should be using Chopper Strikes freely.

It is most important to destroy anything that spawns bugs at this point nearby at this point. The hive at '4', when it spawns, along with any spawning towers. These take total priority over anything else, even guardian nests.

Finally, at the 0:30 minute mark, you probably only have the bottom-most point and perhaps the one next to it. Chopper Strike away, suicidal charges, whatever -- you just need to keep them from capturing the final point for 30 more seconds.

You need 36 BP to make this work. You start with 24, so this means you need to capture 12 more. Destroying the hive at '1' will get you 3; if you can then let the northernmost point be captured, and recapture it along with the two BP crates dropped by chopper, you're good.

If you can't go ahead and do the plan as much as you can, and watch out for extra BP crates to get -- specifically, two will get dropped close to '4' which should be somewhat easy to grab.

Anyways, the plan is this: once you've got your 36 BP, run away to the two bottom most points. On each point, set 6 mine fields, fully surrounding each point (each one centered on one of the lights of a point). Screenshot:



Ta-da, the points are now uncaptureable by the bugs, even when a tower spawner dies right on top of it, thus guaranteeing you a win and the Thou Shalt Not Pass achievement.

Protect the NPCs as they wander off into the dark and deadly world on a set schedule, ignoring all logic and common sense!

(This mission is actually not that bad, especially coming after The Return and Memento Mori.)

Achievements:
- Anabasis: Beat the map

Available training: Riflemen, Shotgunners, Officers, Flamers, Snipers
Available research: Reinforcements, Ammo Supply, Grenades, Robotics, Chopper Strike, Life Support
Available armoury: Minefield, Mortar, Medical Pod, Turrets, Shield Emitter

Map:


Mutations:

• Enraged Guard (1 hive captured)
  
• Enraged Spawn (4 hives captured)
  
• Protohives (6 hives captured)

The first thing to note is that Sarge is a minigunner, and he and his team won't die during the map. He's going to attack hives every 90 seconds or so, and he will destroy each one he attacks. He'll even capture them for you! All you need to do is defend them afterwards, because apparently Sarge is not big on defense.

Sarge's targets are noted on the map in yellow.

The doctor, on the other hand, is *not* a minigunner and *can* die. She will also attack roughly ever 90 seconds, and if you haven't cleared out the aliens ahead of her, she's going to have a bad time. If she dies, you lose.

The doctor's targets are noted on the map in blue. In addition, there will be a transluscent blue line between her and her target at all times, as well as a countdown timer.

(Although you will interact with the biotoxin crates in Tension and Endgame, you cannot interact with them here. You cannot go and get the crates yourself and drag them back to the doctor, for example.)

Your suggested path is noted on the map in green, as normal. Note that in some cases, such as when sarge captures the hive at yellow 2, you should station some sort of defense there regardless of the schedule.

---

To start with, build Grenades and make a marine a shotgunner. Clear the area at green-1 so that the doctor can hit her first target.

Shortly after you clear it, Sarge should capture the hive at yellow-1, giving you 6 more BP. Build Life Support and head for green-2. Capture the BP crate along the way.

Around this time, the doctor should retrieve the first bioweapon crate, giving you 6 more BP. Change a marine to a flamer and attack the hive at green-2, and the bulwark southwest of it. Capture the two BP crates.

If you are having trouble with the enraged spawn, shotgunners and flamers work best. You can also use Chopper Strike to soften up the hive.

Take a moment to see if Sarge has captured the hive at yellow-2. If he has, send a marine there to guard it.

Destroy the towers at green-3, then capture the hive at green-4. At this point and forward, you should have more than enough BP for your needs.

Leave one or two marines on defense at green-4, and destroy the guardian nest just south of it. Then capture the hive at green-5, capture the BP crates, and destroy the towers around blue-3.

Sarge may have captured the hive at yellow-3 now. If so, send someone to defend it. It is around this time you can start getting protohive attacks, so be on the lookout. However, you should have so much BP and so many marines that it should not be a worry. Flamers can destroy protohives very quickly.

Capture the hives at green-6.

Sarge may have destroyed the two hives at yellow-4 now; for some reason, he won't capture them. Check in occasionally -- if they've been destroyed, send someone to capture them both.

Meanwhile, send your team to green-7 (blue-4) and then green-8 (blue-5). If the doctor gets to blue-5 and retrieves the bioweapon crate there, she will return to base and stop moving. At that point, your only pressure is from protohives.

Finally, capture the hives at green-9 if you didn't previously when Sarge destroyed them. If the siege cannon is a bother, hit it with two simultaneous Chopper Strikes.

Capture a seemingly endless stream of crates while pink marines run around destroying your stuff.

Achievements:
Tension: Beat the map
Get Your Own: Win Tension without allowing the aliens to capture a single crate

Available training: Riflemen, Shotgunners, Officers, Flamers, Snipers
Available research: Engineering, Reinforcements, Ammo Supply, Grenades, Robotics, Chopper Strike, Life Support
Available armoury: Minefield, Mortar, Medical Pod, Turrets, Shield Emitter, Siege Cannon

Map:


Mutations: Mutations occur in response to hives being captured, and in response to the aliens capturing crates. Each crate the aliens capture is worth about 2/3 of a hive capture. Unlike the couriers in Preparations, these are not tracked separately -- losing crates to the aliens straight up accelerates what mutations you will see.

• Impact (1 hive captured)
  
• Carapace (2 hives captured)
  
• Spitter Spawn (3 hives captured)
  
• Hive Spite (4 hives captured)
  
• Spitter Guard (5 hives captured)
  
• Clone Strike (6 hives captured)
  
• Regeneration (7 hives captured)
  
• Spore Mines (8 hives captured)
  
• Mimicry (9 hives captured)
  
• Mimic Nest (10 hives captured)
  
• Barriers (11 hives captured)
  
• Necrophage (12 hives captured)

This map is largely built around clones (pink versions of your marines). The very best thing to use against clones are scouts. Unfortunately, you do not get access to the scout upgrade until after this mission is beaten. If you have difficulty getting the Get Your Own achievement on your first runthrough, be aware that it is substantially easier to beat the map and then play again with scouts.

Additionally, although you do not need to take any buffs to beat this map, the extra scout buff you can buy also makes this map much easier.

The walkthrough for this map assumes you have Engineering. If you don't have enough money to buy Engineering, replay previous maps, or play the raid tree of missions (that start with Sudden Strike) to receive enough money. You can do this without Engineering, but it requires a lot of micromanaging in order to replace destroyed turrets.

There are 33 crates scattered throughout the level. Your marines can tow them to the doctor; each crate successfully retrieved nets you 4 BP. However, each time a marine begins to tow one of the crates, three clones will be spawned from a random (usually nearby) hive and will beeline to that marine. You should avoid having three marines pick up three crates simultaneously, since that will spawn nine clones. If a marine towing a crate dies or otherwise drops a crate, three more clones will be spawned when it is next picked up.

(Note that if you have scouts, scouts are visible while towing crates.)

In addition to this, clone teams will be coming from the northeast portion of the map, and will attempt to find crates and drag them off to the northeast. If they are successful in doing this, the aliens gain additional mutations, as described above. The number of clones in these teams, as well as the frequency of their attacks, goes up as you capture more and more crates.

The essential strategy for this map is to be able to tow crates yourself, while repelling clone attacks from the northeast so the aliens get no crates. There are two main ways of doing this:

1. Scouts. If you have the extra scout buff, station the scout somewhere in the northeast, and move around as needed to wherever the clones are. If you have the scout upgrade, because you've already beaten this map, you will eventually want multiple scouts.

2. Engineering + Turrets. If you lack scouts, such as on your initial playthrough, this is the easiest way to deal with clones. Engineering allows you to place turrets remotely, but more importantly, it will auto-rebuild turrets that are destroyed. This is important because the clones can destroy turrets relatively easily, but as long as you have ammo, your turret lines will hold.

The rest of this walkthrough assumes Engineering + Turrets; if you have scouts, placement is similar, just more efficient.

To start the map, build Engineering. Then build two turrets, at the positions marked A and B on the map. The turrets should be placed so that they cover the entire chokepoint (clones can't get by without being fired on), but are not close enough to provoke the spawn towers or be fired upon by the infested turrets or spitter towers.

For your five marines, place one at each X. Your other three marines should head to B. Place them around the turret, and then have one of them grab a crate closest to the aliens. Drag it back to the turret. Three clones will be spawned and will approach -- between your three marines and the turret, they should be quickly dealt with. Repeat twice more with your other two marines. Once all three marines have a crate, drag them back to the doctor.

Around this time, the first clone attack will occur. It should quickly run into one of your turrets. The turret should destroy clones quickly, but may itself be destroyed in turn. This is fine -- Engineering means it to auto-build itself and continue. If necessary, destroy the other turret, place it so it can help destroy the clones, and then destroy it and put it back when the clone team is killed.

With the first 12 BP, build Life Support -- this is to heal your turrets, not your marines. Repeat the entire process, gathering three more crates and dealing with the nine clones spawned. With the next 12 BP, place two more turrets, one at A and one at B. Place them some distance from the original one so that when the clones start using shotguns and flamers they won't hit multiple turrets at once.

Continue getting crates. Your next desired upgrades are Grenades, Ammo Supply, and another marine. This marine should be placed with the turrets at A or B, whichever one you are *not* grabbing crates from.

Ammo Supply is crucial because, very soon, clone teams will be destroying your turrets left and right, and each rebuild with Engineering costs 2 ammo. If you have no ammo, they will not rebuild, and that is how you will lose the Get Your Own achievement. Ammo Supply means that every clone that is killed drops a mini ammo crate that contains 2 ammo -- your marine who is around the turrets can be used to pick these up and you will never want for ammo again.

As you capture crates, the clone attacks will become larger, more frequent, and will start to feature clone shotgunners, flamers, and snipers. Even with 6-8 turrets, they will blow through your line with ease. This is all fine. As long as you have ammo, your turrets will rebuild and keep them from dragging crates back.

Here is a screenshot of the turret defense -- I've already cleared out all of the crates around A, and am now working on those around B.



After you have captured all of the crates, it's time to destroy the hives. Destroy some turrets if you need BP. Hit the hives in order of 1, 2, 3, 4, and 5. I use 2 flamers and 4 shotgunners. You can also use Engineering to place 5-6 turrets around a hive and then march your marines in. For 4 and 5, you may find Chopper Strike useful to soften up the towers, but I just hit them with 8 turrets and that was that.

I don't bother getting the BP crates on this level, since the bioweapon crates give you more BP (and keep the aliens from capturing them). If you have scouts, you can scout up to a BP crate, grab it, turn into a flamer, and drag it back to base, but really, after capturing 33 bioweapon crates, you've got 132 BP anyways.

Kill your former general. Face huge waves of tough aliens. Likely die a whole bunch.

Overall, pretty fun.

Achievements:
- Periapsis: Beat the map
- Bunker Benefactor: Finish Periapsis without losing a bunker

Available training: Riflemen, Shotgunners, Scouts, Officers, Flamers, Snipers
Available research: Engineering, Reinforcements, Ammo Supply, Grenades, Robotics, Chopper Strike, Life Support
Available armoury: Minefield, Mortar, Teleporter, Medical Pod, Turrets, Shield Emitter, Siege Cannon

Map:


Mutations:

• Spore Mines (1 hive captured)
  
• Hive Spit (2 hives captured)
  
• Counterattack (3 hives captured)
  
• Brute Guard (4 hives captured)
  
• Tower Spawner (5 hives captured)
  
• Rust (6 hives captured)
  
• Protohives (7 hives captured)
  
• Regeneration (8 hives captured)
  
• Brute Spawn (9 hives captured)

This map features three bunkers under your control that spawn AI marines, and three bunkers under alien control that spawn clones. The clones will really wreck the AI marines, so if you're not around to handle them, expect your AI allies to die a whole bunch.

Luckily, there's a very easy, and very cheap, way to get rid of them.

Start off by building Chopper Strike, Extra Ammo, and Grenades. Your ammo should quickly fill up; when it does, use three simultaneous Chopper Strikes on the southernmost enemy bunker. It'll be destroyed, and that's a third less clones you need to worry about.

Have your marines take the hive at 1, and use the BP you get from that to build Life Support. By the time that is done, your ammo should be refilled and the Chopper Strike cost should be 0 again -- use three simultaneous strikes to the middle enemy bunker.

Wait until your ammo is refilled and the cost is zero, and destroy the final enemy bunker. Now you don't need to worry about intermittent clone attacks, and your AI allies will be much more effective. In addition, Sarge, an invincible minigunner, will be dropped onto the map near 5. He's not going to capture any hives this time around, but he's a useful distraction that keeps the aliens off of your back.

With that out of the way, attack the hives at 2. If this is difficult to pull off, you can wait for ammo to refill and use Chopper Strikes to soften up the first hive. The second hive should quickly follow.

Get a flamer and some shotguns and destroy the protohive between 2 and 3, and then capture 3. Be sure to grab the 3 BP crates around. Head back to 2, and then capture the hive at 4. Again, Chopper Strike to soften it up if necessary, but it shouldn't be. Capture the 5 BP crates around.

At this point, you start getting tower spawners, so pay attention and send a flamer to remove them when they show up. Chopper Strikes are also very good at removing the towers.

The enemy general likes to attack 4 sometimes. If so, let him come and kill him -- he's only killable if the bunkers are all destroyed and there are no other clones on the map. Two snipers will take him out quite easily.

Take 5. Destroy the guardian nests to the west of 5, and capture the 3 BP crates there. Keep going and take 6. Kill the general if he's not dead already.

Finally, swing down to take 7. With all of the mutations at this point, this fight can be difficult -- use Chopper Strikes to soften up a hive, make sure you have at least one officer, capture the hive, and then use the inspiration to quickly destroy a second hive, and then the third.

All in all, a rather straightforward map.

Play against all the mutations!

Achievements:
- Endgame: Beat the map
- Back from the Dead: Remove 10 (or more) mutations at once

Available training: Riflemen, Shotgunners, Scouts, Officers, Flamers, Snipers, Minigunners
Available research: Engineering, Reinforcements, Ammo Supply, Grenades, Robotics, Chopper Strike, Life Support
Available armoury: Minefield, Mortar, Teleporter, Medical Pod, Turrets, Shield Emitter, Siege Cannon

Map:


Mutations:
The aliens will gain random mutations over time; it is unrelated to your capturing of hives. Any and all mutations are possible on this map.

Scattered throughout the map are bioweapon crates, just like in Tension. Just like in Tension, if a marine picks one up, three clones will be created from the center hive, and will make a beeline to that marine to kill him.

If you drag a bioweapon crate to the center hive, it will remove all mutations, and will pacify the aliens for a period of time (dependent on how many mutations were just removed; the more that were just removed, the longer the period of pacification). During this time, the aliens won't attack or spawn unless you're within their detection radius.

Around the center hive are clones. Every time there is a new mutation, clones are respawned here if necessary. Because of this, when dragging a bioweapon crate to the center, it is best to wait until just after a mutation, send in your scout(s) to headshot the clones, and then send in the crate.

Around the map are enemy-controlled bunkers. Unlike in Periapsis, these will not generate clones, and so are not a priority to be destroyed. However, when you do destroy them, they will begin to generate AI controlled ally marines, which are somewhat useful.

It is highly recommended that you have both the scout and minigunner upgrades from the store before attempting this map.

To start with, build Grenades and Life Support. Have two marines pick up bioweapon crates -- this will spawn six clones at the center. Make the last marine a scout, and send him to take out the clones. He probably can't kill them all before reaching your marines, but he should be able to get most.

When that is done, make the scout into a shotgunner and take the hive at 1. Create a new marine and leave him just south of 1 as defense. With your other five, make your shotgunner into a flamer and attack the hive at 2. When it's captured, make another flamer. Have one flamer destroy the bunker to the east while the other flamer and the other three marines attack the mimic nest to the west.

Regroup when both are destroyed, and capture the hive at 3. Create another marine and station him at 1 as defense.

It is about this time that you should think about removing mutations. Make everyone a rifleman, and then select one marine carrying a bioweapon crate -- make him a flamer. Select two marines are not carrying crates -- make them scouts. Send them into the middle via the chokepoint south of 3. The flamer should destroy the protohive, while the scouts run around attempting to destroy towers -- if they one-shot a tower, great, if not, use a rocket to destroy it. When that's done, the scouts should destroy any clones on the east side of the hive. When the coast is clear, send the flamer towing the crate to the hive; when the mutations have been removed, grab the two BP crates on the east side and then have everyone regroup at 3.

During the pacification period, make the scouts back into riflemen and then make a minigunner, and take the hives at 4, as well as destroying the protohive there. Then turn your attention to destroying the two guardian hives around 5. Flamer + 2 minigunners is fine for this purpose; alternatively, you can use snipers and then switch to minigunners when the guardians are dead. When both nests are destroyed, capture the two BP crates, and leave a marine just north of 5 to stand guard.

Take everyone else and go to capture 6. Destroy the bunker to get some more AI assistance.

The hives at 7 may prove difficult -- two hives in proximity, plus a siege cannon. I roll in with flamers and minigunners and don't have too much of a problem. You may also try Chopper Strikes (either on the hives or on the siege cannon) or Engineering + a turret to take out the siege cannon. Whatever works for you. Capture the two BP crates and destroy the third enemy bunker.

Destroy the guardian nest at 8, and take stock. It is probably time to remove mutations again, so use scouts to headshot the clones, and take the opportunity to also clean up any towers just lying around. Drop off the bioweapon crate, and pick up the BP crates while you're here.

Take the hive at 9 during pacification, and then destroy the bulwark and the bunker.

Destroy the protohive just north of 10, but do not capture 10 yet, and do not destroy the bunker to the south of it.

The goal here is, with just 10 remaining as the only uncaptured hive, to let ten mutations build up so that you can get Back from the Dead. You do not receive new mutations once all hives are captured, so if that's the case, you'll have to play the map again. Have someone grab a bioweapon crate and deal with the clone attack. Split your team up into those that are to the northeast and those that are to the northwest of 10. Minigunners are fine, as are shotgunners -- the idea is containment. Another possibility is to use Engineering + 6 mine fields around 10 to destroy all aliens coming out of it.

Then you just wait until there are ten mutations. The only worrisome ones are Burrowing Hive (annoying), and any of the spawner ones, which will likely involve using minigunners to clean up whatever spawned.

When there are ten mutations, use scouts to clear out clones from the middle and drop off the bioweapon crate. Capture 10 in the aftermath. Destroy the bunker, too, because why not.

At the point where you have captured all hives, there will be no new mutations. Destroy the main hive and win.

---

If at any point during the map you are having trouble with a mutation, use a bioweapon crate. Despite what the NPCs say, they are more than plentiful. This is especially true if you get Burrowing Hive or Guardian Nest.

If you are being pushed back, consider using a bioweapon crate and then attacking during the pacification phase. Otherwise, try to fall back to the last area you can hold, regroup, and try again. Especially after you've taken 5-6 hives, putting down Robotics can be useful in stopping annoying bugs from sneaking by your defense and having to be dealt with. Engineering also makes it easy to lay down a temporary turret wherever it's needed.

Keep an eye on the mutations, and for those mutations that occur periodically. Your marine on defense right by the beginning of the map is fine against bugs, but will get rolled during a clone strike. Be vigilant, and change him as necessary to deal with the situation (eg, scout for a clone strike, minigunner for a nest, etc).

Aside from the campaign missions, which are described in detail in the walkthrough above, you have these assorted random of missions through the campaign map:

Ruins, Abyss, and Terminus are normal missions where you must capture and control all of the points on the map. Ruins is the easiest and Terminus is the hardest, in terms of how much BP you have to start with and how many mutations you're up against. In addition, in Terminus mode, the mutations are weighted against you instead of being random. See the Terminus section for more.

Ruins Raid, Abyss Raid, and Terminus Raid are similar to Ruins, Abyss, and Terminus, except the emphasis is on destroying hives instead of controlling points.

If you destroy a hive, a larger, sturdier bunker will be placed on it automatically. If the aliens destroy this bunker, you will lose some amount of money and the point will be removed instead of recaptured.

Winning a raid map with all points is harder than winning a normal map; however, just winning a map without worrying about defense or protecting bunkers is easier than a normal map.

Survival maps start out with you controlling all points. Roughly every two minutes, an increasing number of hives will spawn (starting with one, then two, then three, etc) randomly throughout the map, along with increasing mutations. If the aliens capture a point, it becomes a hive as normal, but then the point is removed -- it can never be recaptured. You win when you control zero points (outside of surrendering, there is no way to lose a survival map).

During the early parts of the map, BP crates will spawn along with the hives, and additional BP crates will spawn when a hive is destroyed. As time goes on, BP crates become less and less frequent.

Elite Survival is similar, but gains mutations faster. The mutations may also be weighted against the player as in Terminus, but this is not confirmed.

It is possible to play survival pretty much forever, if you have a nice corner to hole up in.

Hunt maps are like normal Raid, Abyss, and Terminus maps, having the same increases in difficulty, except that every so often, a hive crawler is spawned, and every time you destroy a hive, a hive crawler is spawned. If the hive crawler isn't killed, it will make a new hive.

Destroying the hive crawler is all about being in front of it, as opposed to specific forces or types of marines.

Hives on points will *not* respawn if destroyed, even if the point is left uncaptured. This makes hunt missions much easier than comparable Ruins, Abyss, or Terminus missions, as you can destroy a number of hives without capturing them to keep the number of mutations down.

The weekly challenges are available from the main menu, not the campaign menu. The weekly challenge maps are what they say on the tin -- every week, a new challenge. Each map has a leaderboard, which is again, wiped weekly.

No matter where you are in the campaign, everything is unlocked in the weekly challenge maps. In addition, even if you have not purchased the Trickster's Arsenal DLC, the Abilities menu and mutators will be present in the maps, in order to ensure a level playing field.

During a given week, the weekly challenge map will always be the same, and the mutations used will be predetermined and consistent through each playthrough. This, again, is to ensure a level playing field -- it also means that once you've played a map once, you can attack it again with a better grasp on the strategy.

Bronze, Silver, and Gold correspond to Ruins, Abyss, and Terminus difficulty, and obey the same rules, except that the map will always be the same, and the mutations are predetermined.

The scoring is based on how quickly you can capture all points -- the faster you do it, the higher the score; specifically, the score is 5,000 points per hive captured, -1 point per second. Points are not deducted while the game is paused, so feel free to pause with abandon.

Gold maps especially tend to be a right pain in the ass, oftentimes including charming combinations like guardians without snipers, hordes of aliens without flamers, or all of the spawner mutations at once.

Maximizing Score: It's all about speed. In most Bronze/Silver maps, it used to be about using Officers to get people places quickly -- now it's about using Teleport Jump. Look at the mutations the enemy has and figure out the best way to quickly destroy hives. Chopper Strike, avoiding Bulwarks/Guardian Nest/Mimic Nest spawns, and making use of Officer's inspirations are all key points in shaving off time.

Gold works slightly differently, just because it tends to be exponentially harder. It is a rare Bronze map that is not beaten in under three minutes; many Gold maps have a high score of 10+ minutes.

This is the same as Elite Survival. Like Bronze, Silver, and Gold, mutations are predetermined for that week's map -- however, hive spawning is still at least somewhat random.

Unlike Elite Survival, there is a 15 minute time limit for Horde.

Like Bronze, Silver, and Gold, you gain 5,000 points per hive destroyed, and gain (not lose) 10 points per second. Note that there is no penalty for losing a point. In practice, lasting the entire 15 minutes is usually trivial, so the real challenge is destroying as many hives as possible.

Maximizing Points: The trick to ensuring a top-level score on the leaderboard is this: destroyed hives are worth 5,000 points. When you lose a point, a hive is spawned there, which can then be destroyed for another 5,000 points. Although you might think that the best strategy would be to protect all points, you will, in fact, want to lose all of them but one.

The caveat is that you need all hives to be destroyed by the time the timer reaches zero -- otherwise, fewer hives will spawn to replace them, which means less points. So you only want to let your points be captured when you are sure you can still destroy all hives before the time runs out.

The final piece is that at the last wave, you only have 30 seconds -- you will not be able to destroy all of the hives in this time, so it is a matter of being able to destroy as many as you can in those 30 seconds. Officer inspiration is a must.

The Ironman challenge is only available to owners of the Trickster's Arsenal DLC. It is like the Hunt campaign missions in that crawlers will spawn according to a timer, and everytime a hive is destroyed.

However, it is different in that dead marines will not respawn, and if you destroy a building, you will only receive half of the BP back. If you are careless it is easy to get into a non-winnable state.

In addition to getting points for capturing hives, BP crates are also dropped by some destroyed towers and hives.

The scoring for Ironman is 5,000 points for each captured (not just destroyed) hive, and -1 point for each second as normal. In addition to this, you will lose 1,000 points every time a crawler is spawned (either from a hive being destroyed, or due to the timer). You gain 1,000 points back if it's destroyed, but if it spawns a hive, those points are gone forever. Although it will never show a score below 0, the game does keep track of your negative score.

Maximizing Points: You must destroy every crawler. At a loss of 1,000 points, it is better to take ten minutes (-600 points) longer than it is to let a crawler go (-1,000 points).

So do not attack a hive unless you have a clear plan of how you are going to kill the crawler it spawns.

Besides that, go as fast as possible.

Note that, unlike every other map, hives will not reappear on points. It takes longer, but is easier, to run around and destroy hives without capturing the points, because you still gain BP, but the aliens do not gain mutations. It is not fast enough to be competitive for the #1 spot, but it easily gets you in the top ten.

This section of the guide focuses on the Terminus maps, under the assumption that if you can handle those you can handle anything else the game throws at you.

Terminus is a standard map that features:
- 12 BP and 5 Riflemen to start
- 4 BP crates surrounded by towers
- 9 Hives
- 3 Nests

Additionally, the following happens during map creation:
- Two items are randomly locked in the Training, Research, or Armoury menus. You can't use the two locked items for this mission.
- The aliens are given two mutations.

After this, every time a hive is captured, the aliens are given another mutation. However, unlike other maps where the mutation is random, on Terminus the mutations are weighted against whatever strategy you are using. Using flamers? More likely to see Bombardment, Impact, or Neurotoxins. Using turrets? More likely to see Infestation or Rust. Using minigunners? More likely to see Clone Strike. Etc.

The first thing to remember is that the aliens will not get further mutations until you have captured another hive. Because of this, you should do as much as you can without capturing another hive as possible.

So instead, let's start by getting those BP crates.

If you have scouts, make one of your marines and scout and wander them over to a BP crate. Order them to fire on each tower in turn -- they will destroy roughly half of them in a single hit. The ones that don't get destroyed in a single hit can't be killed by the scout's weapon. Once you've done this on all four towers, use rockets ('G' key) to destroy the rest. You now have an unguarded BP crate. Change the scout into a flamer (if available) or officer (if not).

If you don't have scouts, use a flamer+medical pod instead. Have him move directly towards the BP crate in question, skirting hives in the way. When he gets there, destroy the four towers. The medical pod should take care of any damage he sustained along the way.

In either case, you should now have an unguarded BP crate you can tow back to base. Do that, skirting hives in the way. It's ok to take some damage along the way. It's ok to die, as long as you make progress. However, if you don't think you can make any progress at all, you have a few options:
1: Use scout or Engineering to leave a medical pod near where you'll take damage
2: Use scout or Engineering to leave one or two minefields near the source of bugs who might get in your way
3. Chopper Strike bugs in your way
Somehow, you should get the BP crate back to base and get 3 more BP. Clean up any structures (medical pods, minefields, etc) that are no longer relevant.

Repeat for the next three BP crates. You can have a marine build the Grenades upgrade back at base which will also help in getting the crates home.

At the end of this, you should have 24 BP total (12 to start, +12 from crates).

Next up is destroying nests, bulwarks, etc. There are two main options:

1: Use Ammo Supply + Chopper Strike. Wait until the helicopter cost is 0, and you have the full 20 ammo, and then call 3 simultaneous choppers onto the target. This should destroy an bulwark or nest, aside from a guardian nest.
2: Set 3 marines to be scouts, and move them to surround the target in question. Change them to flamers and let them toast it. If you don't have access to scouts, three flamers can probably destroy it anyway.
3: If you don't have flamers, send three scouts to the target, in a triangle formation where two of the marines are close to the target and the third is farther away. Change the back one to a minigunner. Change the front two to shotgunners, unless it's a mimic nest, in which case they should stay as scouts.

Repeat until all nests are destroyed.

Now the fun begins. There's two valid approaches for how to determine which hives to capture first:

1) Capture hives that will make defense easier -- if you have two hives to the left of you and seven to the right, it'll be easier to take the two to the left rather than waging a two-front war the entire map
2) Capture a group of three hives now while there are few mutations.

If a group of three hives is nearby, I will tend to go for it first. It is easier to take now, before it gets Bombardment / Spitter Guard / Guardians / etc. Otherwise, I'll go for containment and ease of defense.

Your first capture or two should be relatively straightforward. I tend to leave a rifleman at base; with the other 4 and my 24 BP, I tend to build Grenades, change two of the riflemen into scouts and move them to opposite sides of the hive, then send my other two riflemen in. When the riflemen get in range, I change the scouts to flamers.

An alternate approach is Grenades, minigunner, shotgunner, rifleman, rifleman.

If Grenades is not available, I go for either Life Support or an extra marine.

If going for a group of three hives, I will build Ammo Supply + Chopper Strike and get my marines into position. I'll launch three simultaneous strikes on the nearest hive, then turn two of the marines into an officer and a minigunner. Have your riflemen and officer attack-move to the hive, but focus the minigunner on the hive directly. When the hive falls and the officer's inspiration kicks in, immediately focus the minigunner onto the next hive and repeat.

In general, one rifleman with grenades can defend a base. However, as the mutations pile up, the chance you get Bulwarks, Burrowing Hive, Clone Strike, Guardian Nest, Mimic Nest, Protohives, or Tower Spawner goes up significantly. Once one of those appears, you must pay careful attention to the map because any of those will be enough to overwhelm a defense and destroy a base.

If you see a spawner from Tower Spawner, let it come to you, kill it, and then use a flamer or minigunner on the towers.

If you see any other spawner, try to hit it while it is still close to its hive. Two Chopper Strikes or a sniper work best for this; if correctly done, the spawner's structure will not spawn (unless it's a Tower Spawner, which will always make towers). If it does spawn a structure, clean up the nest with chopper strikes + minigunner or flamer.

Clone strikes should be met with a scout, unless it's clone minigunners. Then use a sniper or a minigunner of your own.

For burrowing hives, note the position of the warning bubbles, and move a flamer towards them at earliest opportunity. A flamer will destroy the hive by itself if he's close enough to where the hive spawns. He may require some other backup to handle the bugs.

I will pause whatever offense I have underway in order to deal with one of the above threats.

Completed all of the campaign maps? Got all the achievements? Regularly run Terminus missions for some laid-back, stress-free entertainment?

Here's some other things you can do. Unless otherwise noted, these can be done without any buffs.

The first step is to beat them; the second step is to beat them with a score approximating the top score. I personally don't enjoy replaying a challenge to try to squeeze ten extra seconds out of it, but if you're off of the top score by a hundred points or more, there's some room for massive improvement. See if you can figure out what it is.

Complete all of the campaign maps without taking any casualties, including Memento Mori.

Complete Preparations without any couriers dying. I have yet to be able to do this without using buffs.

Complete Memento Mori while controlling all of the points. I have yet to be able to do this without using buffs.

Complete Endgame without using any bioweapon crates.

Complete a Terminus (harder) or Terminus Raid (easier) map using no marines other than Riflemen.

Start a new profile, and see how far you can get in the game without buying anything from the shop (no upgrades, no buffs, not even bunkers). I've gone through Memento Mori.