Attack:
Aurora Beam - 10% chance to lower attack by 1 stage.
Baby-Doll Eyes - 100% chance to lower attack by 1 stage.
Charm - 100% chance to lower attack by 2 stages.
Feather Dance - 100% chance to lower attack by 2 stages.
Growl - 100% chance to lower attack by 1 stage.
Intimidate - 100% chance to lower all opposing Pokemon's attack by 1 stage.
King's Shield - When hit by a contact move, lowers the attacker's attack by 2 stages.
Memento - Causes user to faint and lowers targets attack and special attack by 2 stages.
Noble Roar - 100% chance to lower attack and special attack by 1 stage.
Parting Shot - 100% chance to lower attack and special attack by 1 stage.
Play Nice - 100% chance to lower attack and special attack by 1 stage.
Power Split - Averages the attack and special attack stats between target and user.
Rototiller - Raises attack and special attack of all grass types by 1 stage.
Secret Power - 30% chance to lower attack by 1 stage when used in water.
Swagger - 100% chance to raise attack by 2 stages and confuse.
Tickle - 100% chance to lower attack and defense by 1 stage.
Venom Drench - Lowers a poisoned target's attack, special attack and speed by 1 stage.
Defense:
Crunch - 20% chance to lower defense by 1 stage. (Special Defense in Generations II and III)
Crush Claw - 50% chance to lower defense by 1 stage.
Flower Shield - Raises defense of all grass types by 1 stage.
Guard Split - Averages the defense and special defense stats between target and user.
Iron Tail - 30% chance to lower defense by 1 stage.
Leer - 100% chance to lower defense by 1 stage.
Rock Smash - 50% chance to lower defense by 1 stage.
Screech - 100% chance to lower defense by 2 stages.
Tail Whip - 100% chance to lower defense by 1 stage.
Tickle - 100% chance to lower attack and defense by 1 stage.
Special Attack:
Captivate - Lowers special attack by 2 stages if the user is the same gender as the target.
Confide - 100% chance to lower special attack by 1 stage.
Eerie Impulse - 100% chance to lower special attack by 2 stages.
Flatter - 100% chance to raise special attack by 1 stage and confuse.
Memento - Causes user to faint and lowers targets attack and special attack by 2 stages.
Mist Ball - 50% chance to lower special attack by 1 stage.
Moonblast - 30% chance to lower special attack by 1 stage.
Mystical Fire - 100% chance to lower special attack by 1 stage.
Noble Roar - 100% chance to lower attack and special attack by 1 stage.
Parting Shot - 100% chance to lower attack and special attack by 1 stage.
Play Nice - 100% chance to lower attack and special attack by 1 stage.
Power Split - Averages the attack and special attack stats between target and user.
Rototiller - Raises attack and special attack of all grass types by 1 stage.
Secret Power - 30% chance to lower special attack by 1 stage when used in Misty Terrain.
Snarl - 100% chance to lower special attack by 1 stage.
Venom Drench - Lowers a poisoned target's attack, special attack and speed by 1 stage.
Special Defense:
Acid - 10% chance to lower special defense by 1 stage.
Acid Spray - 100% chance to lower special defense by 2 stages.
Bug Buzz - 10% chance to lower special defense by 1 stage.
Earth Power - 10% chance to lower special defense by 1 stage.
Energy Ball - 10% chance to lower special defense by 1 stage.
Fake Tears - 100% chance to lower special defense by 2 stages.
Flash Cannon - 10% chance to lower special defense by 1 stage.
Focus Blast - 10% chance to lower special defense by 1 stage.
Guard Split - Averages the defense and special defense stats between target and user.
Luster Purge - 50% chance to lower special defense by 1 stage.
Metal Sound - 100% chance to lower special defense by 2 stages.
Psychic - 10% chance to lower special defense by 1 stage.
Seed Flare - 40% chance to lower special defense by 2 stages.
Shadow Ball - 20% chance to lower special defense by 1 stage.
Speed
Bubble - 10% chance to lower speed by 1 stage.
Bubble Beam - 10% chance to lower speed by 1 stage.
Bulldoze - 100% chance to lower speed by 1 stage.
Constrict - 10% chance to lower speed by 1 stage.
Cotton Spore - 100% chance to lower speed by 2 stages.
Glaciate - 100% chance to lower speed by 1 stage.
Gooey - Lowers speed 1 stage upon contact with Pokemon that have this ability.
Icy Wind - 100% chance to lower speed by 1 stage.
Low Sweep - 100% chance to lower speed by 1 stage.
Mud Shot - 100% chance to lower speed by 1 stage.
Rock Tomb - 100% chance to lower speed by 1 stage.
Scary Face - 100% chance to lower speed by 2 stages.
Secret Power - 30% chance to lower speed by 1 stage when used in 'murky water & puddles'
Sticky Web - Lowers speed by 1 stage upon switching in.
String Shot - 100% chance to lower speed by 2 stages.
Venom Drench - Lowers a poisoned target's attack, special attack and speed by 1 stage.
Evasion & Accuracy
Defog - 100% chance to lower evasion by 1 stage.
Flash - 100% chance to lower accuracy by 1 stage.
Gravity - Lowers evasion of all Pokemon by 2 stages while in effect.
Kinesis - 100% chance to lower accuracy by 1 stage.
Mirror Shot - 30% chance to lower accuracy by 1 stage.
Mud Bomb - 30% chance to lower accuracy by 1 stage.
Mud-Slap - 100% chance to lower accuracy by 1 stage.
Muddy Water - 30% chance to lower accuracy by 1 stage.
Night Daze - 40% chance to lower accuracy by 1 stage.
Octazooka - 50% chance to lower accuracy by 1 stage.
Sand Attack - 100% chance to lower accuracy by 1 stage.
Secret Power - 30% chance to lower accuracy by 1 stage when used in sand and badlands.
Sweet Scent - 100% chance to lower evasion by 2 stages.
Smokescreen - 100% chance to lower accuracy by 1 stage.
Odd Cases
Contrary - Reverses stat changes. For example, Flatter lowers Special Attack by 1 stage, instead of raising it.
Trick/Switcheroo + Stat-Changing Item - You can use Trick or Switcheroo to switch a stat-changing item to your target. For example, you can switch an Eviolite to a non-fully evolved Pokemon and raise its Defense and Special Defense.
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