Pokémon Gold and Silver Versions/New Features/Type and Stat Changes

Two new types were introduced: Steel and Dark. These two types serve to balance the Psychic type, which previously was only weak to moves. In addition, the Steel and Dark types also balanced the Fighting type, which was only super effective against Normal-, Ice-, and Pokémon; Steel and Dark are both weak to Fighting-type moves. Steel-type Pokémon are known for their very high defense; they are highly resistant to many types and their moves are strong against Ice- and Rock-type Pokémon. Dark-type Pokémon are immune to Psychic-type moves and have moves with malicious-sounding names, such as (previously ) and, which are super-effective against Psychic-type Pokémon. Dark-type Pokémon are also strong against Pokémon, thus being the only type that has an attack advantage over Ghost-type Pokémon besides Ghost-type moves themselves. Dark-type Pokémon are also weak to Bug-type attacks.

Some type match-ups were changed as well. In Generation I Ghost-type moves had no effect on Psychic-type Pokémon; this was changed to super-effective as it was in the anime. moves were previously super effective against Bug-type Pokémon, and Bug-type moves were super effective against Poison-type Pokémon; this was changed to Poison doing normal damage to Bug and Bug becoming not very effective against Poison, seriously limiting the effectiveness and usage of both types. Ice-type moves were also made not very effective against Pokémon (previously doing normal damage). Four moves had their types changed:, previously Normal-type, became a move; , previously Normal-type, became a  move; , previously Normal-type, became a  move; , previously Normal-type, became a  move. Two Pokémon, and, changed from being Electric type to being Electric/Steel.

Another major change from the original games was the splitting of the stat into  and. Again, this increased aspects of strategy, for Pokémon were now more specialized. Some were good special attackers, while others were better physical attackers; the same now held true for Defense and Special Defense. For example, has a decent Special stat in Generation I, but in all later games, has a decent Special Attack, but low Special Defense.