Cards (pods in CEO) are used by players to accomplish pretty much everything in Cosmic Encounter. Cards are used to attack, defend, make deals and cause various effects - anything that is not accomplished by moving ships or using an alien power.
Cards are drawn from various decks. The main deck of cards used in the game is the cosmic deck, from which players' hands are dealt. Other decks used are the destiny deck, which determines the players that will encounter each other, and the reward deck, which contains special cards that defensive allies can draw.
Players keep their cards in their hands, secret from the other players. Each player starts the game with a hand of eight cards (or seven, depending on the edition) and cannot get a new one until all the cards are played or discarded; this makes card management very important. During the game, all players may count the number of cards in all players' hands and make whatever claims they want about the cards in their own hands, but the cards themselves may not be shown to other players unless a power or game effect says otherwise. Cards that are set aside (such as Miser's hoard) or placed on the table (such as a player's selected encounter card or owned tech cards) are not considered to be part of a player's hand.