Does an aura on an illegal permanent fall off immediately or wait until the next state-based action check?

State-based actions (SBAs) are the game's automatic 'cleanup crew.' They are not continuous effects; they only apply at specific checkpoints: whenever a player would receive priority, before certain steps and phases begin, and similar moments defined by the rules. An Aura on an illegal permanent does not fall off the moment it becomes illegal — it persists until the next SBA check.

CR 704.5n states: 'If an Aura is attached to an object or player it can't legally enchant, it becomes unattached and remains on the battlefield, then is put into its owner's graveyard as a state-based action.' The Aura briefly becomes 'unattached' and then is put into the graveyard — all as part of the same SBA check, so it never floats free for players to interact with in that window.

This matters because in between SBA checks — for example, during the resolution of a spell or ability — an Aura can temporarily be on an illegal permanent without yet being removed. It is only removed when the game finally pauses to check SBAs (typically when a player would receive priority next).

Concrete example: Your opponent controls a 1/1 creature with Unholy Strength (+2/+1) on it. You cast Pyroclasm, dealing 2 damage to all creatures. The creature's toughness becomes 0 while Pyroclasm is still resolving, but the Aura does not fall off mid-resolution. Once Pyroclasm finishes resolving and SBAs are checked, both the creature (lethally damaged) and the Aura (now on an illegal/nonexistent object) are moved to the graveyard at the same time.

Key rules to remember: CR 704.3 explains when SBAs are checked, and CR 704.5n covers the specific Aura rule. Because SBAs are checked simultaneously, multiple illegal situations (dead creature, orphaned Aura) are all cleaned up in the same pass.