Trigger You're the target of a spell you're aware of.
You attempt to counteract the triggering spell. If the spell would be counteracted, it instead continues with the caster as a target instead of you. Spell riposte can't affect spells that aren't targeted (such as area spells).
Traits
Manipulate
You must physically manipulate an item or make gestures to use an action with this trait. Creatures without a suitable appendage can't perform actions with this trait. Manipulate actions often trigger reactions.