Individual values, IVs for short, sometimes also known as determinant values, DVs for short, are the Pokémon equivalent of genes. They are instrumental in determining the stats of a Pokémon, being responsible for the large variation in stats among untrained Pokémon of the same species. Each of the six battle stats has an IV associated with it, with that IV coming into calculation alongside the Pokémon's base stats and EVs to determine the actual stat number. A Pokémon's IVs are determined when it is generated by the game; when it is obtained as an Egg from the Pokémon Day Care, encountered in the wild, or given to the player by an NPC.
In Generation III, IVs would have a range of 0-31, with HP and Special Defense getting their own individually-determined IVs. The formula for calculation of stats by IVs was also changed, as with the IV system the EV system was also modified, and Natures, newly-introduced, now modified certain stats either by raising or lowering them by 10%. The personality value handles a Pokémon's gender, Shiny status, and several other aspects.
The Generation III-on determination of stats follows the following two formulas:
The IVs are now all stored together as a single 32-bit integer, separate from the equally-large personality value, which is used to determine other aspects of a Pokémon. This integer's highest bits, single numbers, determine which of two Abilities a Pokémon has (if it has potential to have more than one) and whether or not the Pokémon is an unhatched egg or not. The remaining 30 bits are the IVs, five bits apiece, in the order of Sp. Def, Sp. Atk, Speed, Defense, Attack, and HP.
For two Marill caught on Route 120:
|Marill A||Thick Fat||No||46||22||40||47||22||101|
|Marill B||Huge Power||No||48||24||34||50||23||97|
If the Pokémon's species can have only one Ability in Generation III, the Ability bit is forced to 0 by the game, as being 1 in this instance would cause the Pokémon in question to have "No ability" listed as their ability.