The card system is an economy system where you are given a limited number of each class (excluding default). You get 3 of the 5 main classes in the game, and your team shares a pool of 8 grenades and 8 smokes. If you pick a card and die, the card stays on the map for the remainder of the round for either team to pick up. Whichever team picks it up gets it added to their deck for the next round. If neither team picks it up then the card is lost until halftime when you switch sides. The default card gets a free grenade and smoke, the operator(shotgun) class gets a free smoke, and the heavy(automatic rifle) class gets a free grenade.