When Grudge is used, if the user faints as the direct result of an attack, the move which causes the user to faint will lose all of its PP. This move's effect only works if the user faints before making another move. Grudge does not activate for damage that occurs at the end of the turn, including damage from Leech Seed, Toxic, Sandstorm, Hail, and Future Sight.
If powered up by a Ghostium Z into Z-Grudge, all of the opponent's moves will target the user for the rest of the turn, if possible.
Grudge can also be used as part of a Pokémon Contest combination, with the user gaining extra four appeal points if move Curse was used in the prior turn. It is also part of a Contest Spectacular combination with the user gaining an extra three appeal points if any of the moves Encore, Taunt or Torment was used in the prior turn.