Potencies (Rule Card 1)

Potencies are powerful spells that are cast directly
from a player's own library. Announce a potency
only during your turn any time you could play a sorcery and only once per turn. Announcing a
potency goes onto the stack, then each other
player must indicate if they are responding
(putting anything else onto the stack). Once all responses have resolved and all players indicate
they are not responding, the potency is the only remaining spell on top of the stack; search your library for the nam