HM slave is a term used within parts of the fandom to refer to a Pokémon in a Trainer's party that is not used for battling, but to provide navigational support through the use of field moves—generally those taught by Hidden Machine. HM slaves will typically have all four move slots occupied with field moves, allowing smooth passage through caves, across oceans, or past other obstacles at the expense of their battling capabilities.
Many Pokémon are able to learn a wide array of HM moves. Some trends persist throughout regions and games: Pokémon are commonly used as HM slaves because of the abundance of Normal-type HMs. -type- and Pokémon may be suitable HM slaves in some regions, depending on the HM distribution. -typeBibarel is considered by some players as one of the best HM slaves, with the ability to learn six out of eight HM moves in Sinnoh, seven out of eight in Johto, five out of six in Unova, four out of five in Kalos, and six out of seven in Hoenn. While infrequently used for these purposes, Legendary Pokémon can also typically learn many HM moves. Through Sketch, Smeargle can learn any HM move.
As Pokémon cannot learn more than four moves, Trainers may require two or more HM slaves in order to achieve sufficient coverage.
- List of HMs by generation
- List of Pokémon by field move