- For a complete list, see List of HMs.
An HM (short for Hidden Machine) is a type of item introduced in Generation I.
Description[]
HMs are discs containing a certain field move, so it can teach a certain Pokémon a move that can be used outside of battle. From this, the player can reach otherwise inaccessible locations, or areas of the current location that features exclusive items and Pokémon. Because HMs are required to progress, the player can neither dispose or them nor sell them.
HMs have a similar counterpart titled TMs, which do not contain a field move. Prior to Generation V, TMs can be used only once before breaking, unlike HMs. There are a lot fewer HMs than TMs, ranging usually between five to eight. HMs have nearly identical sprites to TMs aside from a small circle being drawn on top.
HMs are usable on the field even if the Pokémon that knows it has fainted or has run out of PP for that move. To activate an HM, the player has to stand in front of the corresponding obstacle, access the party menu, and select a Pokémon that knows the HM. For some obstacles, the player can activate the HM without accessing the menu.
In most games, the usage of HMs outside of battle is regulated by Gym Badges, most of which give the player the ability to use a certain HM on the field. HMs are always usable in battle, regardless of how many Gym Badges the player has.
Unlike other moves, a Pokémon cannot easily forget a HM by replacing it with another move. The player can only get a Pokémon to forget how to use an HM with the help of a Move Deleter or by leaving the Pokémon at a Pokémon Day Care, where it naturally learns moves upon leveling up. There is even a term titled HM Slave, which refers to a Pokémon that can only use HMs, eliminating the necessity of teaching an HM to another Pokémon in the player's party.
As with TMs, the numbered HMs are frequently associated with a different move between appearances.
HMs have stopped appearing since Generation VII, in favor of replacements such as Poké Rides and Secret Techniques.
Appearances[]
Core series[]
Generation I[]
In the Generation I games, it is not possible for a Pokémon to forget an HM through any means.
Generation III[]
Pokémon in a Generation III game cannot be transferred to a Generation IV game if it knows an HM, requiring the assistance of the Move Deleter to have the Pokémon forget the HM.
Generation IV and remakes[]
In Pokémon Diamond Version and Pokémon Pearl Version, Pokémon Platinum Version, and the remakes Pokémon Brilliant Diamond and Pokémon Shining Pearl, there are eight HMs.
In Pokémon Brilliant Diamond and Pokémon Shining Pearl, the Pokétch serves as the functional replacement for the eight HMs in the original Pokémon Diamond Version and Pokémon Pearl Version, with the moves being added to the app upon acquiring the respective TM for the first time. Field moves that are not originally HMs, such as Flash and Dig, must still be activated from the Pokémon menu screen.
Generation V[]
In Generation V, the usage of HMs on the field has become largely unnecessary. In Pokémon Black Version and Pokémon White Version, the only time that the player is required to HM is at the Dreamyard, where HM01 (Cut) is necessary to get rid of a tree that blocks the path. All other HMs can be used to reach optional areas, usually allowing for the player to obtain extra items.
HMs can be used at any time outside of battle, regardless of how many Gym Badges the player has.
If the player transfers Pokémon from a Generation IV game through the Poké Transfer, it cannot know any HMs.
Spinoffs[]
HMs appear in the Pokémon Mystery Dungeon series. They are similar to TMs since a Pokémon can forget an HM easily and sell it for only 1 Poké. In situations where an HM can open a new area, certain items can provide this function as well, but are only single-use.
Manga[]
Pokémon Pocket Monsters[]
Though a variety of HMs do not appear in chapter 16 of Pokémon Pocket Monsters, Green shows off his Charizard's ability to use Fly because of HM02, so Red goes to get his own HM02.
Pocket Monsters Zensho[]
An HM, specifically Cut, is mentioned by Lt. Surge in chapter 4 of Pocket Monsters Zensho, in which he remembers using the move to cut down a tree, and Red later receives the HM from the SS Anne captain.