In the second generation of games, many mechanics were added. These include using Held Items in battle, weather, new items, Pokemon Breeding, and the first case of version exclusive legendaries. On top of that, this generation introduced the Dark Type and Steel Type, as well as changed the type advantage/disadvantage list. It also changed and improved a few things from the first, including but not limited to, making Gust a Flying-type attack instead of Normal, making Whirlwind and Roar usable in trainer battles, and allowing the opponent to still attack when Wrapped, Bound, or Clamped.