Hustle

Hustle increases the ability-bearer's Attack by 50%, however, it also reduces the Accuracy of all Physical moves by 20%.

Game descriptions

Ruby, Sapphire, FireRed, LeafGreen, Emerald:Trades accuracy for power.
Diamond, Pearl, Platinum, HeartGold, SoulSilver:Boosts the Attack stat, but lowers accuracy.
Black, White, Black 2, White 2:Boosts the Attack stat, but lowers accuracy.
X, Y, O.Ruby, A.Sapphire:Boosts the Attack stat, but lowers accuracy.
Sun, Moon, Ultra Sun, Ultra Moon:Boosts the Attack stat, but lowers accuracy.
Sword, Shield, B.Diamond, S.Pearl:Boosts the Attack stat, but lowers accuracy.
Scarlet, Violet:Boosts the Pokémon’s Attack stat but lowers its accuracy.