This move can’t be used. It’s recommended that this move is forgotten. Once forgotten, this move can’t be remembered.
Effect[]
Trick-or-Treat adds the target's type with the Ghost-type, regardless of whether it is a dual typed Pokémon. Due to this, as long as the foe has no type that resists Ghost-type moves, this move can be used along with a damaging Ghost-type to deal super effective damage to a Pokémon who would initially not be weak to Ghost.
If the Pokémon already has a third type added by an effect, like Soak, that type is replaced by the Ghost-type. It has no effect if the targeted Pokémon is already a Ghost-type.