What is the name of Pokémon’s second generation of games?

Pokémon’s second generation of games is called Generation II.

Generation II began with Pokémon Gold and Silver, released in Japan in 1999 for the Game Boy Color. These games expanded the original formula with 100 new Pokémon, bringing the Pokédex total from 151 to 251.

The games introduced the Johto region, day-and-night time progression, held items, breeding, Pokémon eggs, two new types, and the friendship mechanic. They also connected to the earlier Kanto region, allowing players to revisit the setting of Pokémon Red, Green, Blue, and Yellow after completing the main Johto adventure.

Pokémon Crystal was the enhanced third version of the same generation. Generation II is sometimes confused with the second Pokémon anime season, but the generation label specifically refers to a group of video games and their associated Pokémon, mechanics, and regions.