Pokémon Diamond

Pokémon Diamond introduced Sinnoh with 107 new Pokémon, the Underground fossil system, and the series' long-awaited physical/special split. This randomizer applies to all 493 Pokémon available in Diamond — Sinnoh routes that are normally packed with the same handful of mons get completely shaken up. The Underground and Super Contests still work as normal.

Diamond's physical/special split makes randomized movepools more mechanically interesting than in earlier generations — a Pokémon assigned Fire-type moves now has them categorized correctly as physical or special based on the individual move. The Underground fossil system still yields randomized Pokémon when fossils are revived, adding an extra layer of discovery beyond standard route encounters.