502. Untap Step

502.1.First, all phased-in permanents with phasing that the active player controls phase out, and all phased-out permanents that the active player controlled when they phased out phase in. This all happens simultaneously. This turn-based action doesn’t use the stack. See rule 702.26, “Phasing.”

502.2.Second, if it’s day and the previous turn’s active player didn’t cast any spells during that turn, it becomes night. If it’s night and the previous turn’s active player cast two or more spells during that turn, it becomes day. If it’s neither day nor night, this check doesn’t happen and it remains neither. This turn-based action doesn’t use the stack. See rule 731, “Day and Night.”

502.3.Third, the active player determines which permanents they control will untap. Then they untap them all simultaneously. This turn-based action doesn’t use the stack. Normally, all of a player’s permanents untap, but effects can keep one or more of a player’s permanents from untapping.

502.4.No player receives priority during the untap step, so no spells can be cast or resolve and no abilities can be activated or resolve. Any ability that triggers during this step will be held until the next time a player would receive priority, which is usually during the upkeep step. (See rule 503, “Upkeep Step.”)