The games introduce Raikou, Entei, and Suicune, some new types of legendary Pokémon that wander around Johto, changing locations frequently. They can be tracked by the Pokédex once encountered, and will always attempt to flee, but will retain HP loss. In addition there is the possibility of encountering a shiny Pokémon, which have a different coloration than normal Pokémon of their species, and appear very rarely. Two new Pokémon types were added, the Steel-type and the Dark-type. Steel-type Pokémon are immune to Poison-type moves, and they have very high defense and resistance to other types, while Dark-type Pokémon are immune to Psychic-type moves and are strong against Psychic-type Pokémon (which provides an offensive strategy, formerly absent against Psychic-types), as well as having few weaknesses. In "Gold" and "Silver", new moves were added, but Pokémon knowing these moves are not allowed to be traded to the first generation games. To solve this, a move deleter was introduced, capable of erasing moves known by the Pokémon. Another major change was the splitting of the "Special" stat into "Special Attack" and "Special Defense", which increased aspects of strategy.