Generation
In terms of the Pokémon video game franchise, a generation is a grouping of games that debuted at or around the same time and were compatible with the other games in that timeframe, allowing the same number of species of Pokémon to be captured.
More technically, it refers to the groupings of games which had the same battle mechanics: Generation I is characterised by the 15-type type system, Generation II introduces two new types Steel and Dark, Generation III brings changes to the IV and EV system and adds things such as abilities, and Generation IV redefines the difference between Physical and Special as one based on the move, rather than the type.
Currently, there are four Generations of Pokémon games.
| Generation | Main games | Battle games | Number of Pokémon | ||
|---|---|---|---|---|---|
| Japanese releases | English releases | Japanese releases | English releases | ||
| I | Red and Green (early 1996) Blue (late 1996) Yellow (1998) |
Red and Blue (1998) Yellow (1999) |
Stadium (1998) Stadium 2 (1999) |
Stadium (2000) | 151 |
| II | Gold and Silver (1999) Crystal (2000) |
Gold and Silver (2000) Crystal (2001) |
Stadium GS (2000) | Stadium 2 (2001) | 251 |
| III | Ruby and Sapphire (2002) FireRed and LeafGreen (early 2004) Emerald (late 2004) |
Ruby and Sapphire (2003) FireRed and LeafGreen (2004) Emerald (2005) |
Box (early 2003) Colosseum (late 2003) XD (2005) |
Colosseum (early 2004) Box (mid 2004) XD (2005) |
386 |
| IV | Diamond and Pearl (2006) | Diamond and Pearl (2007) | Battle Revolution (2006) | Battle Revolution (2007) | 493 |
Generations I and II are compatible with each other, but not with Generations III and IV. Similarly, Generations III and IV are compatible with one another, but not compatible with Generations I and II.
