Magic: The Gathering is a collectible card game with detailed and, at times, complex rules. Knowledge of the game's rules is necessary to play the game.
Each player uses their own deck to play the game. In most formats, a deck must have a minimum of 60 cards; there is no maximum deck size, but you must be able to shuffle it alone. With the exception of basic lands, only four cards with the same name can be in a deck, unless otherwise stated (An example would be: Relentless Rats). Some gameplay formats have exceptions or additional limitations to the above rules. In tournaments, players may be allowed the use of a sideboard containing up to 15 cards. Sideboard cards can be swapped for cards in the main deck in between games against the same opponent.
At the beginning of a game, each player shuffles his or her deck. Players then decide who will start, using any mutually agreeable method (flipping a coin, for example). Each player then draws seven cards from his or her library to form his or her starting hand. In turn order, each player may then decide to mulligan; that player shuffles his or her hand and library together and draws a new hand of one fewer card. A player can do this all the way down to a zero-card hand if he or she wishes, drawing one fewer card each time. In multiplayer games, players can mulligan for free one time, drawing seven cards a second time. Any further mulligans draw one card fewer each time, as normal.
A player wins the game by eliminating all opponents. Players typically begin the game with 20 life and lose when any of the following conditions are met:
At any given time, every card is located in one of the following "zones":
Library: The portion of the player's deck that is kept face down and is normally in random order (shuffled). When drawing a card, it is always the top card of the library. This is often erroneously referred to as a player's deck. However, the rules of Magic state that all cards in play (on the battlefield), in a player's hand, in the graveyard, exiled by any means, and even in the sideboard technically make up the player's "deck".
Hand: A player's hand of cards that can be played. They are kept hidden from other players. If a player has more than seven cards in hand at the end of his or her turn, any extras must be discarded.
Battlefield: The zone where permanents (see Types of cards) are placed and stay until otherwise removed. Unlike other zones, the battlefield is shared by all players.