From Glitch City Laboratories
The Sketch glitch, or rarely the Metronome glitch, refers to a glitch in Pokémon Gold, Pokémon Silver and Pokémon Crystal which allows one to permanently give a Pokémon capable of using the move Transform, or Metronome any move, presuming that the user's Pokémon has temporarily learned the move Sketch.
The Sketch glitch is caused by the fact that the move Sketch was designed to permanently change the moveset of a particular Pokémon within battle but also the moveset of that same Pokémon outside of battle. Nintendo intended this move to be used by only Smeargle, however Sketch still has its original effect even if another Pokémon has temporarily learned that move within battle through a move such as Transform.
- Another player (as wild Smeargle will normally have Sketch as their only move. The move will fail if the player attempts to copy the move Sketch.)
- The other player needs to have a Smeargle with the move Sketch, but also another move.
- Preferably, the player's Pokémon has to be faster than Smeargle.
- An opponent with the desirable move to be copied.
- Enter a battle against another player with the Pokémon with Transform or Metronome first in the party.
- The opponent should have a Smeargle with Sketch and at least one other move first in his or her party.
- Transform into Smeargle, or use Metronome until the move Transform is used, whilst Smeargle uses another move which does not faint the user's Pokémon, such as Splash.
- The player should now have the move Sketch, so he or she can then Sketch any move that the enemy Pokémon knows.
- At the end of the battle, the move Metronome or Transform will have permanently been replaced by the sketched move.
- Q Trick
- Mimic glitch
- Rage glitch