311.2 Plane cards remain in the command zone throughout the game, both while they’re part of a planar deck and while they’re face up. They’re not permanents. They can’t be cast. If a plane card would leave the command zone, it remains in the command zone.
311.3 Plane subtypes are listed after a long dash, and may be multiple words: “Plane — Serra’s Realm.” All words after the dash are, collectively, a single subtype. Planar subtypes are called planar types. A plane can have only one subtype. See rule 205.3n for the complete list of planar types.
311.4 A plane card may have any number of static, triggered, and/or activated abilities. As long as a plane card is face up in the command zone, its static abilities affect the game, its triggered abilities may trigger, and its activated abilities may be activated.
311.5 The controller of a face-up plane card is the player designated as the planar controller. Normally, the planar controller is whoever the active player is. However, if the current planar controller would leave the game, instead the next player in turn order that wouldn’t leave the game becomes the planar controller, then the old planar controller leaves the game. The new planar controller retains that designation until they leave the game or a different player becomes the active player, whichever comes first.
311.7 Each plane card has a triggered ability that triggers “Whenever chaos ensues.” These are called chaos abilities. Each one is indicated by a chaos symbol to the left of the ability, though the symbol itself has no special rules meaning. This ability triggers if the chaos symbol is rolled on the planar die (see rule 901.9b), if a resolving spell or ability says that chaos ensues, or if a resolving spell or ability states that chaos ensues for a particular object. In the last case, the chaos ability can trigger even if that plane card is still in the planar deck but revealed. A chaos ability is controlled by the current planar controller.