Historical Rules · 16 January 2026
Rule 500.5
Official source text from the 16 January 2026 Rules release
As a step or phase ends, if there are effects that last until the end of that step or phase, those effects expire. Then any unspent mana left in a player’s mana pool empties. This is a turn-based action that doesn’t use the stack (see rule 703.4q).