Jamming

Jamming is a term used in Pokémon Contests and is a feature only in Generation III; it refers to when an appeal can lower the appeal points of the other Pokémon in the contest by the number of black hearts represented above the number of appeal points the move makes.

If not executed correctly it only says that the move messed up, and it still gains appeal points and any other extra, for example, if a move that affects all Pokémon after the user is played last. On the other hand, if the move backfires on the user, it causes them to lose appeal points.

Moves which can jam

Move Category Contest Type Jam Absorb Special Smart Grass ♥♥♥ Acid Special Smart Poison ♥♥♥♥ Air Cutter Special Cool Flying ♥ Arm Thrust Physical Tough Fighting ♥ Astonish Physical Smart Ghost ♥♥♥ Aurora Beam Special Beauty Ice ♥ Beat Up Physical Smart Dark ♥ Bite Physical Tough Dark ♥♥♥ Blast Burn Special Beauty Fire ♥♥♥♥ Body Slam Physical Tough Normal ♥♥♥♥ Bone Club Physical Tough Ground ♥ Brick Break Physical Cool Fighting ♥♥♥♥ Bubble Special Cute Water ♥♥ BubbleBeam Special Beauty Water ♥♥♥ Bullet Seed Physical Cool Grass ♥ Charm Status Cute Normal ♥ Confusion Special Smart Psychic ♥♥♥ Constrict Physical Tough Normal ♥♥♥ Cotton Spore Status Beauty Grass ♥ Crunch Physical Tough Dark ♥♥♥♥ Crush Claw Physical Cool Normal ♥♥♥♥ Cut Physical Cool Normal ♥ Dizzy Punch Physical Cool Fighting ♥♥♥♥ DoubleSlap Physical Tough Normal ♥ Dragon Claw Physical Cool Dragon ♥ DragonBreath Special Cool Dragon ♥♥♥ Dream Eater Special Smart Psychic ♥♥ DynamicPunch Physical Cool Normal ♥ Earthquake Physical Tough Ground ♥♥♥ Extrasensory Special Cool Psychic ♥♥♥♥ Fake Out Physical Cute Ghost ♥ False Swipe Physical Cool Normal ♥♥♥ Fissure Physical Tough Ground ♥ Focus Energy Status Cool Normal ♥♥♥ Frenzy Plant Special Cool Grass ♥♥♥♥ Fury Attack Physical Cool Normal ♥ Fury Swipes Physical Tough Normal ♥ Giga Drain Special Smart Grass ♥ Glare Status Tough Normal ♥♥♥ GrassWhistle Status Smart Grass ♥♥♥ Guillotine Physical Cool Normal ♥ Hail Status Beauty Ice ♥♥♥ Headbutt Physical Tough Normal ♥♥♥ Horn Drill Physical Cool Normal ♥ Hydro Cannon Special Beauty Water ♥♥♥♥ Hyper Beam Special Cool Normal ♥♥♥♥ Hyper Fang Physical Cool Normal ♥♥♥♥ Hyper Voice Special Cool Normal ♥♥♥ Hypnosis Status Smart Psychic ♥♥♥ Ice Beam Special Beauty Ice ♥ Icicle Spear Physical Beauty Ice ♥ Icy Wind Special Beauty Ice ♥♥♥ Iron Tail Physical Cool Steel ♥♥♥♥ Knock Off Physical Smart Dark ♥♥♥♥ Leech Life Status Smart Bug ♥♥♥ Leech Seed Status Smart Grass ♥♥ Lick Physical Tough Normal ♥♥♥♥ Lovely Kiss Status Beauty Normal ♥♥♥ Low Kick Physical Tough Fighting ♥♥♥♥ Luster Purge Special Smart Psychic ♥♥♥ Mega Drain Special Smart Grass ♥♥♥♥ Metal Sound Status Smart Steel ♥♥♥ Mist Ball Special Smart Ice ♥♥♥♥ Mud Shot Special Cute Ground ♥♥♥ Muddy Water Special Tough Water ♥ Mud-Slap Special Tough Ground ♥ Needle Arm Physical Smart Grass ♥♥♥♥ Night Shade Special Smart Ghost ♥ Nightmare Status Smart Ghost ♥♥♥ Octazooka Special Tough Water ♥ Outrage Physical Cool Normal ♥♥♥♥ Pain Split Status Smart Normal ♥♥♥♥ Perish Song Status Beauty Ghost ♥ Petal Dance Special Beauty Grass ♥♥♥♥ Pin Missile Physical Smart Bug ♥ Poison Sting Physical Smart Poison ♥♥♥ Psychic Special Smart Psychic ♥♥♥ Psywave Special Smart Psychic ♥ Pursuit Physical Smart Dark ♥ Recover Status Smart Psychic ♥ Rock Slide Physical Tough Rock ♥♥♥ Rolling Kick Physical Cool Fighting ♥♥♥ Sand-Attack Status Cute Ground ♥ Scary Face Status Smart Normal ♥ Screech Status Smart Normal ♥♥♥ Seismic Toss Physical Tough Fighting ♥ Sheer Cold Special Beauty Ice ♥ Skull Bash Physical Tough Normal ♥♥♥♥ Sky Uppercut Physical Cool Fighting ♥ Slam Physical Tough Normal ♥ Sleep Powder Status Smart Normal ♥♥♥ Sludge Special Tough Poison ♥♥♥♥ Sludge Bomb Special Tough Poison ♥ SmellingSalt Physical Smart Normal ♥♥♥ Smog Special Tough Poison ♥♥♥ Snatch Status Smart Dark ♥ Spark Physical Cool Electric ♥♥♥♥ Spike Cannon Physical Cool Normal ♥ Spore Status Beauty Grass ♥♥♥ Stomp Physical Tough Normal ♥♥♥♥ Strength Physical Tough Normal ♥ String Shot Status Smart Bug ♥♥♥ Stun Spore Status Cool Normal ♥ Super Fang Physical Smart Normal ♥ Sweet Scent Status Smart Normal ♥♥♥ Teeter Dance Status Cute Psychic ♥♥♥♥ Thrash Physical Tough Normal ♥♥♥♥ Thunder Special Cool Electric ♥♥ Thunder Wave Status Cool Electric ♥ Tri Attack Special Beauty Normal ♥♥ Twineedle Physical Cool Bug ♥♥♥ Will-O-Wisp Status Beauty Fire ♥♥♥♥

Trivia

• The Normal-type has the most moves that can jam, 36.
• Physical moves have the most moves that can jam, 49.
• Smart contests have the most moves that can jam, 34.
• Out of all of the moves that can jam, only five can remove two appeal points. Out of those five, only Leech Seed is a Status move. The rest are all Special moves.