Ok. So during your escapades in Special Missions and Multiplayer you will earn XP. XP levels you up and gives you a REWARD OF VALOR! HUZZAH!

Using a Reward of Valor does two things:

1) You get a renown injection to your account. I think it is between 4k-7k. Don't quote me on that, but I think that is the ball park. You can then use this renown to purchase upgrades to your multiplayer characters. Keep in mind that just because you buy a reliability upgrade for your Storm Bolter on your Apothecary, it ONLY UNLOCKS THAT UPGRADE FOR THE APOTHECARY'S STORM BOLTER! Thats it, all other classes that use a Storm Bolter will not get that upgrade!

2) You recieve a random item for a random class. This can be anything from an armor or weapon skin, a banner (which doesn't do much, place with spacebar while looking at the ground) or even armor or weapon upgrades.

Your single player progress and multiplayer progress are seperate.

When you stand still and fight you are probably going to fall victim to hordes and hordes of enemies who will eventually overrun you. This is bad, get through a door, block it and keep moving. The obvious exception is escort missions and missions where you have to stay in a small area to secure it or something.

Firstly, this is obvious, but secondly, when you complete objectives, two things happen. The first is that your team is revived! So if you aren't the Chaplain, you can still get the whole team back before their cooldown just by finishing an objective! Its usually not as easy as it sounds, but you don't really have many options unless you can find a room that has no spawns in it and lock yourself in there. Which is a viable stratedgy. The second thing that happens is a warp rift appears! Exciting! If you are wounded and your fresh ass Apothecary has just come back, his skills are on cool down, so hop in that rift to get back to full health. You can also change your classes and loadouts at this point!

Seriously, have at least one guy watching your backs, xeno filth run from everywhere, don't get four guns in one direction unless your backs are safe, because they usually arent.

The Tactical Marine and Chaplains are kind of funny. By funny I mean the Tactical Marine is completely overshadowed by the Chaplain. The Tac Marine can Revive one Terminator, Cast One Shield or Summon a Servo Skull. The Chaplain can revive the entire team, make them all invulnerable or give them damage reflection. All of them. You may wonder: Why the Tactical then? Does he have shorter cool downs? NO! He does not. His cooldowns are long boys. So long. I'd say his cooldowns need to be reduced by 60-70 percent to compete with the Chaplain. Unless you really. REALLY love the power fist (Tactical Marine can take a perk to improve the power fist a little bit, not worth it in my opinion.), the Chaplain is the easy choice.

Relics give the entire party 500XP at the end of a mission. Pass or Fail. Relics always appear in the same place every mission. They are super valuable and Relic Runs are a viable way to grind XP.

All classes are viable. With the exception of Chaplain over Tactical, all classes fill a void in your boarding party. So choose a class you enjoy, but keep in mind, while a team full of Heavy Terminators is likely to be spectacular, they will not have healing or reviving outside of completing objectives. So it is usually a good idea to have at the very least an Apothecary looking after the team! Speaking of which, always look after your support boys! Their weapons aren't as shooty as say the Heavy's. So you need to really get after it to protect them. Not to say they can't hold their own, because many weapons are viable and can sort issues out on their own.

Ok, this needs to be broken down a little bit. So be prepared for this!

A) ARMORS
These are cosmetic skins for your class, pick one you like, because it makes you look pretty. And half the battle is looking pretty, the other half is lots of violence!

B) COOL DOWN REDUCERS
This set of traits will reduce the cooldown on your skills. You can only pick one, so determine which skill is most important to you and save up for the 15K one. Its the only one you need. Lower level tiers do not stack and are not required for progression.

C) EFFECT REDUCERS
This set of traits basically will buff your defenses against a specific source of damage. Again, save for the 15K tier as lower tiers don't stack and aren't required to progress to the last one. It is commonly held that ACID resistance is ideal as that is the damage type that the purple explosive guys deal and at high difficulty they are a big problem. However, thats just a popular opinion, do as you please. If you find yourself being killed alot by a specific type of damage, you may want to use this catergory to fill that shortcoming you've got.

D) EFFECT BOOST ADORNMENTS
This set of traits will buff either Armor, Melee Damage or Ranged Damage. So this is really dependant on your playstyle however being that these are percentage buffs, it would be ideal I think to take Armor over Melee or Ranged if you are using weapons with lower damage as they benefit less that say a Plasma Cannon would over Ranged Damage. You know what I mean? Armor also aids in survivability so thats something that is always useful, but again, it really depends on your playstyle here. Again, you can only take one trait, they don't stack and you don't need lower tiers to get to the higher tiers.

E) TORCH COLORS
This is your flashlight. Press T to turn it off and on. Medium is default. I can only assume Cold would add a bluish hue and warm would add a more amber hue. But I have heard there is no discernable difference.

Ok, so there is a lot to cover on this and I think it probably ought to be its own guide really, but a quick run down of them. Reliability and Ammunition Capacity are universally helpful so they should be among your first upgrades to most platforms. Use muzze devices to enhance a strong aspect of your weapon, or reduce a short coming. Skins and Bayonets look cool and are purely cosmetic. Optical Modules only activate during precision aiming, so keep that in mind when choosing one. Thats the quick and dirty of it guys.

Seriously, Resilience is another universally helpful perk. A 30 percent buff to your hitpoints at each body part is the difference between death/reduced capability and just being maimed pretty good. Now each class has its own set of perks and you can only pick one, so choose wisely. This can enhance your playstyle and I think it could merit its own guide really being that there are between 7 and 9 for each class.

So in closing that is about it. Thats the rough rundown I have prepared and I hope it helps you guys out! Please keep in mind I am by no means a top tier player or expert by most definitions of the words. This guide is designed to give a brand spanking new player a bit of a direction in their starting hours of Multiplayer.