- 720.1 One card (Shahrazad) allows players to play a Magic subgame.
- 720.1a A “subgame” is a completely separate Magic game created by an effect. Essentially, it’s a game within a game. The “main game” is the game in which the spell or ability that created the subgame was cast or activated. The main game is temporarily discontinued while the subgame is in progress. It resumes when the subgame ends.
- 720.1b No effects or definitions created in either the main game or the subgame have any meaning in the other, except as defined by the effect that created the subgame. For example, the effect may say that something happens in the main game to the winner or loser of the subgame.
- 720.2a As a subgame of a Planechase game starts, each player moves their planar deck from the main-game command zone to the subgame command zone and shuffles it. (Face-up plane and phenomenon cards remain in the main-game command zone.)
- 720.2b As a subgame of a Vanguard game starts, each player moves their vanguard card from the main-game command zone to the subgame command zone.
- 720.2c As a subgame of a Commander game starts, each player moves their commander from the main-game command zone (if it’s there) to the subgame command zone.
- 720.2d As a subgame of an Archenemy game starts, the archenemy moves their scheme deck from the main-game command zone to the subgame command zone and shuffles it. (Face-up scheme cards remain in the main-game command zone.)
- 720.4a Some effects can bring cards into a game from outside of it. If a card is brought into a subgame from a main game, abilities in the main game that trigger on objects leaving a main-game zone will trigger, but they won’t be put onto the stack until the main game resumes.
- 720.4b A player’s main-game counters aren’t considered part of the subgame, although the player will still have them when the main game resumes. Similarly, any counters a player gets during a subgame will cease to exist when the subgame ends.
Example: If a card was brought into the subgame either from the main game or from outside the main game, that card will be put into its owner’s main-game library when the subgame ends.
- 720.5a At the end of a subgame of a Planechase game, each face-up plane card or phenomenon card is turned face down and put on the bottom of its owner’s planar deck. Then each player moves their planar deck from the subgame command zone to the main-game command zone and shuffles it.
- 720.5b At the end of a subgame of a Vanguard game, each player moves their vanguard card from the subgame command zone to the main-game command zone. This is an exception to rule 311.2.
- 720.5c At the end of a subgame of a Commander game, each player moves their commander from the subgame command zone (if it’s there) to the main-game command zone.
- 720.5d At the end of a subgame of an Archenemy game, any face-up scheme cards in the subgame command zone are turned face down and put on the bottom of their owner’s scheme deck. Then the archenemy moves their scheme deck from the subgame command zone to the main-game command zone and shuffles it.