askgaming

The Pokémon games have a lot of these. One in particular is that in Generations 3 and 4 they added a mechanic to prevent the player from stranding themself by releasing the last Pokémon they have with certain HM moves.

For example, say your obnoxious younger sibling is mad at you. They "borrow" your game, use Fly to go to the obligatory island town, release all your Pokémon except for the weakest one, sell all your item, and waste the money by repeatedly buying and selling items until you don't have enough to buy anything useful. In Generations 1 and 2 your only real way to get out of this scenario is to trade your remaining Pokémon with one from another cartridge that has either the move Surf or Fly. In Generations 3 and 4 the last Pokémon that knows an essential HM move will refuse to be released. Generations 5 and 6 don't have this feature because there aren't any islands. From 7 onwards the HM system was replaced entirely.