Oracle

Artifact - Equipment 

Whenever equipped creature attacks, it deals damage equal to its power to the player or planeswalker it's attacking.
Equip 3

NederMagic FAQ

Vraag: Is dit combat damage?
Antwoord: Nee. Combat damage is alleen de damage die creatures assignen in de combat damage step van de combat phase.

Tournooi-info

Legal in: Vintage, Legacy, Modern, Commander

Officiele rulings

5/1/2009
This ability triggers and resolves in the declare attackers step. The creature will still deal its combat damage as normal later on during the combat phase.

5/1/2009
When the equipped creature attacks, the first ability will trigger. When that ability resolves, that creature will deal damage equal to its power to player or planeswalker it’s attacking, even if Mage Slayer has left the battlefield or is equipping a different creature by that time.

Decktips