Pokémon data substructures in Generation III

This is the list of Pokémon data substructures in the Generation III Game Boy Advance games, Pokémon Ruby, Sapphire,.

Format
A Pokémon's data is slightly more complex than the rest of the encapsulating structure. It is stored as four distinct substructures, each 12 bytes in length. (The Notes section below explains some of these fields in greater detail.)

Substructure order
The order of the structures is determined by the personality value of the Pokémon modulo 24, as shown below, where G, A, E, and M stand for the substructures growth, attacks, EVs and condition, and miscellaneous, respectively.

Encryption
The four data substructures are stored in an encrypted form. Decrypting the data involves two steps: actually decrypting the data, and validating the decrypted data. To obtain the 32-bit decryption key, the entire Original Trainer ID number must be ed with the personality value of the entry. This key can then be used to decrypt the data by XORing it, 32 bits (or 4 bytes) at a time. To validate the checksum given in the encapsulating Pokémon data structure, the entirety of the four unencrypted data substructures must be summed into a 16-bit value.

PP bonuses
The PP bonuses byte stores the number of times has been increased for each move in the attacks substructure. Each move has two bits, meaning the PP of each move can be increased 0 to 3 times.

Pokérus status
Pokérus status is stored in a single byte, with the upper and lower halves representing distinct values. Any value from 0 to 15 is valid for the strain, with 0 indicating that the Pokémon does not have Pokérus at all. The number of days can be any value from 0 to 4, although for some "strains", some of those higher values are also invalid. If any bit is set in the "strain" and the number of days is at 0, the Pokémon has been "cured" of Pokérus, as indicated by a small black dot on the Pokémon's status screen.

Origins
Trainer gender tells the game how to color the name of the Pokémon's Original Trainer on the Pokémon's status screen. If Level met is 0, it is interpreted as the Pokémon having been hatched from an ; however, the games only differentiate a hatched Pokémon from other Pokémon if its current Trainer is the Pokémon's Original Trainer. If a hatched Pokémon is traded, its origin text on the status screen is displayed just like a caught Pokémon's and will not say "Hatched" or "Egg".

IVs, Egg, and Ability
IVs for each of the stats from HP to Special Defense take up the lowest 30 bits of this field, each IV taking 5 bits. Bit 30 is a 1 if the Pokémon is still an Egg or 0 otherwise. Bit 31 indicates the Ability the Pokémon has: 0 indicates its first Ability, while 1 indicates its second Ability (if it has one).

In the table below, bit 0 is the least significant bit of the 32-bit field and bit 31 is the most significant.

Ribbons and Obedience
For most of the Ribbons, a value of 0 indicates that the Pokémon does not have the Ribbon while 1 indicates that it does. For the Ribbons, the values 1 to 4 indicate that the Pokémon has the Ribbon or Ribbons for (respectively) the Normal, Super, Hyper, and Master Ranks of that Contest.

The last 6 possible spots for Ribbons are variable. The data identifying what Ribbons these spots correspond to is stored elsewhere. The full list of possibilities for these can be seen here. The only two of these special Ribbons that remain reliably obtainable are those and.

The highest bit of this field, bit 31, determines the obedience of and. If this bit is not set, Mew and Deoxys cannot be traded to or from Pokémon FireRed, LeafGreen, or Emerald, and will always disobey the player in battle in those games (except in link battles). If this bit is set on a Pokémon that is transferred to a later generation, the Pokémon will be treated as having had a fateful encounter.

Links

 * PokemonMakerV4x Help and 80 bytes Make a Pokémon