Ordeal of Purphoros | Magic: The Gathering
Formats Ordeal of Purphoros is Legal in
Official Oracle Text for Ordeal of Purphoros
Whenever enchanted creature attacks, put a +1/+1 counter on it. Then if it has three or more +1/+1 counters on it, sacrifice Ordeal of Purphoros.
When you sacrifice Ordeal of Purphoros, it deals 3 damage to target creature or player.
Official Rulings for Ordeal of Purphoros
9/15/2013 : The check of whether the enchanted creature has three or more +1/+1 counters on it happens as part of the resolution of the attack triggered ability. If the third +1/+1 counter is put on the enchanted creature any other way, you won’t sacrifice the Ordeal until the next time the creature attacks.
9/15/2013 : If you sacrifice the Ordeal in some other way, its last ability will trigger.