Heavy Metal doubles the Pokémon's weight in battle. This increased weight affects the following moves:
- Grass Knot: Deals more damage to Heavy Metal Pokémon.
- Heat Crash: Deals more damage when used by Heavy Metal Pokémon, but they receive less damage from it.
- Heavy Slam: Deals more damage when used by Heavy Metal Pokémon, but they receive less damage from it.
- Low Kick: Deals more damage to Heavy Metal Pokémon.
