702.9. Mispayment for Cost [Warning]: A player pays a cost underpaying its power or energy cost, or uses the incorrect domain to pay a power cost.
702.9.a. Errors of this sort are generally public, and all players are expected to be mindful of game state.
702.9.b. Remedies:
702.9.b.1. Perform a simple rewind if possible, to the moment before the card was played.
702.9.b.2. If a simple rewind is not possible, correct the cost paid if possible, by exhausting, or recycling runes as needed.
702.9.b.3. If rewinding is not possible, instruct the players to continue playing.