Titanfall has these things called burn cards that give you a perk that lasts until you die. It's similar to the Call of Duty perks you can choose, but burn cards are a lot more limiting in that you don't have the effects the whole round (unless you don't die) and once you use it, they're gone.
Burn cards can do things such as improve weapon effectiveness, increase your character's abilities. and decrease the time to get a Titan. You have to choose from your stack of cards which ones you want to take into battle before the round begins. Early on you'll only be able to hold one burn card, but a level 11 you can equip up to a maximum of three cards.
The cards are an interesting way to do a perk system and you'll get new cards at the end of rounds or if you accomplish some tasks. I don't know how well this will work yet, but I am happy to see that these cards aren't permanent for the round so hopefully they don't become overwhelmingly powerful when in use.