In a potentially huge shake-up for the Pokémon series, upcoming games Sun and Moon look like they'll ditch HMs in the traditional sense.
HMs are Pokémon abilities which you need to explore the game's world. Cut, for example, allows you to clear trees from your path. Surf is used to swim. Fly is used to fast-travel.
The downside to HMs, however, is that you need specific Pokémon in your squad that can use them, and then need to sacrifice one of their move slots so an HM can be learnt.
Pokémon Sun and Moon appear to have removed the need for traditional HMs by replacing them with summonable Ride Pokémon which perform the same tasks.
In the game's new demo, available to download now, players can call upon a Tauros to run through and break blocks, similar to the HM Rock Smash.
The full game will offer Charizard to replace Fly and a Lapras to replace Surf, among others. These are not part of your squad but can be summoned at any time.
Previously, players often kept one of their six-Pokémon party just for HMs, but this meant these "HM slaves" were being included not because players wanted a particular species in their squad, or that they would be useful at all in competitive matches.
There's no sign of HMs in the demo - or in its code, which includes numerous items and Pokémon not meant to be seen until the full game launches.
It is still possible that the full Sun and Moon include HMs as well as these Ride Pokémon - but they would be entirely redundant. It's also extremely unlikely as they would have to be manually hidden in the demo's code, something which hasn't been done for actual in-game secrets.
All in all, the sidelining of HMs is a very good thing - and one of many changes in Sun and Moon which refresh the Pokémon formula.