Which Pokémon generation first introduced the Dark and Steel types?

Generation II was the first Pokémon generation to introduce the Dark and Steel types. They debuted in Pokémon Gold and Silver, which expanded the battle system beyond the original games’ type chart.

The two types helped address the dominance of Psychic-type Pokémon in Generation I. Dark-type moves were especially effective against Psychic Pokémon, while Steel Pokémon generally brought strong defensive characteristics and several useful resistances. Their addition changed team-building and battle strategy.

Generation II also introduced other major features, including Pokémon breeding, Baby Pokémon, and Shiny Pokémon. The games added 100 new species, bringing the series total from 151 to 251.

Gold and Silver were first released in Japan for the Game Boy Color on November 21, 1999. Their story takes place mainly in Johto, but players can later revisit Kanto, the setting of the original games. Generation II is therefore associated with both a new region and a direct continuation of the first adventure.