Core series
A version of the Pokémon games is a Pokémon game, up to present, always released on a Nintendo handheld system, which follows the now-standard model of a player's journey through a specific region to collect all of the Pokémon. Collectively, the seventeen games released with the suffix "version" are known by fans as the main series of Pokémon games.
Version formula
What makes a Pokémon game a "version", aside from the label on the box and game media, is the standard plot which is shared by all of them. The player begins the game in a small town, having no Pokémon of their own. Through a course of events, they will come into contact with their region's native Pokémon professor, who will then allow them to keep a starter Pokémon of their choice. The starter Pokémon is always one of a group of three, a Template:Type2, Template:Type2, or Template:Type2, and the character who will become the player's rival will choose or already have the Pokémon whose type is super effective against that of the player's choice. The sole exception to this is Pokémon Yellow, in which the player starts with Pikachu and the rival starts with Eevee.
It is at this point where the storyline of all seventeen diverge. The player is allowed to journey across the entire region, capturing any wild Pokémon they choose to, and using a party they assemble to take on the eight Gym Leaders of the region. Alongside encounters with both other Trainers and repeated interactions with their rival, a villainous team will arrive to cause trouble early on in the player's quest, touting plans to take over the world and sometimes capture legendary Pokémon to do their bidding.
After all eight Gym Leaders have been defeated, with each of their Badges allowing for the use of a specific HM move outside of battle (in the later games), the player can head to the Pokémon League, where the Elite Four and Champion await challengers. In regions other than Kanto, the first encountered region, the player will be required to climb waterfalls to reach their destination.
Though the game is technically over as soon as the player has defeated the Champion, the player's other task of completing the Pokédex remains (also obtaining the other badges in Generation II and HeartGold and SoulSilver in Generation IV). After this has been done (in Generation III and onward, on both the regional and national level), the player will receive a diploma from the Game Freak employees in the game. Starting in Generation III, a new task is added in order to fully complete the game: obtaining all Trainer card stars.
Mascots
On the boxart for each game, one Pokémon, always introduced during the generation that game is a part of, will appear. This Pokémon has become known by fans as a version mascot, and beginning in Generation II, has always (with the exception of FireRed and LeafGreen, remakes of the Generation I games) been a legendary Pokémon available in that game at the climax of the storyline.
Relation to one another
When a generation of Pokémon games begins, a pair of games, seen as counterparts to one another, is always released. These paired versions feature the same exact storyline as each other, but the Pokémon available in either one is different: one game may be missing the Template:Type2 Electabuzz, while the other may not have the Template:Type2 Magmar. These Pokémon, due to their usual exclusivity to one or two of the games in a generation, are typically known as version-exclusive Pokémon. These Pokémon must be traded between games in order to complete the Pokédex, a feature that has encouraged collaboration among players since the series began.
A later third game, usually to conclude the generation, is released with several, usually minor, storyline tweaks, but with the same basic plot and taking place in the same region. Like the first two games, it will always be missing some of the Pokémon (though will likely contain some of those missing from one of the other two), and so, players of this third version must link together with the original pair to complete the Pokédex.
Generation III was the first generation which contained the unprecedented release of two sets of paired versions, first Pokémon Ruby and Sapphire, and then later Pokémon FireRed and LeafGreen, as well as the first which did not contain a third version for one of its storylines (the Hoenn-based Ruby and Sapphire were later joined by Emerald, however, Kanto's storyline did not receive a tuned-up third game). This was later mimicked by Generation IV, which featured a similar setup, except with the order of the remakes and the third version of the initial pair inverted.
| Paired versions | Third version | |
|---|---|---|
| Generation I | ||
| Japan | ||
 Red |
 Green |
 Blue |
 Yellow | ||
| North America, Europe and Australia | ||
Red |
Blue |
Yellow |
| Generation II | ||
 Gold |
 Silver |
 Crystal |
| Generation III | ||
 Ruby |
 Sapphire |
 Emerald |
FireRed |
LeafGreen |
|
| Generation IV | ||
 Diamond |
 Pearl |
 Platinum |
HeartGold |
SoulSilver |
|
Trivia
- Each generation's third version does not use its mascot's official Ken Sugimori artwork. Blastoise (Japanese), Pikachu (Japanese and English), Suicune, Rayquaza, and Giratina use specially made artwork.
- FireRed and LeafGreen Versions, Gold and Silver Versions and HeartGold and SoulSilver Versions also use specially made artwork.
- Generation II was the only generation which only had two main versions and one third version worldwide. Generation I had Blue as a third version and Yellow as an added fourth in Japan, Generation III had the remakes of Red and Green, and Generation IV has HeartGold and SoulSilver.
