Casting a CardLightning Strike, targeting my friend's Dragon's Eye Sentry. He Negates it. I also have an Akroan Crusader and Monastery Swiftspear on the battlefield. He says I don't get a prowess trigger, because the spell wasn't cast. I know that it triggers prowess, but he wanted proof. Can someone find the official ruling? He also wants to know if, say, I casted Hammerhand on an Akroan Crusader, would I get a token?
601.2h Once the steps described in 601.2ag are completed, the spell becomes cast. Any abilities that trigger when a spell is cast or put onto the stack trigger at this time. If the spell's controller had priority before casting it, he or she gets priority.
Prowess triggers as soon as the casting process is complete, and the prowess ability is put onto the stack before any player is able to respond. Once on the stack, the ability exists independently of its source and of the trigger event. Countering the spell that triggered the prowess ability will not counter the prowess ability, nor will it retroactively undo the cast. The spell was still cast; it just didn't resolve.
April 9, 2015 5:54 p.m.
Really no official rules have to be cited here. The reminder text for both Heroic and Prowess tell you that both trigger on the casting of a spell. Since they trigger from the cast, there's no way to stop the ability from going through unless you play something like Trickbind or Voidslime to directly counter the ability. When you cast a spell that'd trigger one of the abilities, the ability immediately enters the stack on top of the spell you cast.