Knock Off

Knock Off is a Dark-type move introduced in Generation 3.

Values by generation

From PokeAPI's change history. Up to Generation 3, physical or special depends on the type. Highlighted cells changed from the previous generation.

Generation	Type	Category	Power	Accuracy	PP	Priority
Generation 3	Dark	Special	20	100	20	+0
Generation 4	Dark	Physical	20	100	20	+0
Generation 5	Dark	Physical	20	100	20	+0
Generation 6	Dark	Physical	65	100	20	+0
Generation 7	Dark	Physical	65	100	20	+0
Generation 8	Dark	Physical	65	100	20	+0
Generation 9	Dark	Physical	65	100	20	+0

Ruby / Sapphire · Emerald	Knocks down the foe’s held item to prevent its use.
FireRed / LeafGreen	Knocks down the foe’s held item to prevent its use during the battle.
Diamond / Pearl · Platinum · HeartGold / SoulSilver	The user slaps down the foe’s held item, preventing the item from being used during the battle.
Black / White · Black 2 / White 2	The user slaps down the target’s held item, preventing that item from being used in the battle.
X / Y · Omega Ruby / Alpha Sapphire · Sun / Moon · Ultra Sun / Ultra Moon · Let’s Go, Pikachu! / Let’s Go, Eevee! · Sword / Shield	The user slaps down the target’s held item, and that item can’t be used in that battle. The move does more damage if the target has a held item.
Legends: Arceus	The user slaps down the target's held item, and that item can't be used in that battle. The move does more damage if the target has a held item.
Scarlet / Violet	The user slaps down the target's held item, making it unusable for that battle. This move does more damage if the target has a held item.

Scarlet / Violet · Scarlet: The Teal Mask / Violet: The Teal Mask · Scarlet: The Indigo Disk / Violet: The Indigo Disk	TM181
Legends: Z-A	TM45

All versions combined; see each Pokémon's page for game-by-game details.

Sources : PokeAPI (moves, move_changelog, move_flavor_text, pokemon_moves, machines)