Pokémon species data structure (Generation III)

The Pokémon species data structure is a 28-byte structure that determines all information inherent to a Pokémon species, such as base stats, types, Egg Groups, and EV yield. Every Pokémon species in the Generation III games has a data structure stored in the game's ROM.

Notes

Base Stats
	type	offset
Base HP	byte	0
Base Attack	byte	1
Base Defense	byte	2
Base Speed	byte	3
Base Sp. Attack	byte	4
Base Sp. Defense	byte	5
Type 1	byte	6
Type 2	byte	7
Catch rate	byte	8
Base Exp. yield	byte	9
Effort yield	word	10
Item 1	word	12
Item 2	word	14
Gender	byte	16
Egg cycles	byte	17
Base friendship	byte	18
Level-up type	byte	19
Egg Group 1	byte	20
Egg Group 2	byte	21
Ability 1	byte	22
Ability 2	byte	23
Safari Zone rate	byte	24
Color and Flip	byte	25
Padding*	word	26.

Missing from this structure are moves known at Level 1, and TM and HM flags, which are stored elsewhere.

Types

The types are associated with the following values:

Value Type 0 Normal 1 Fighting 2 Flying 3 Poison 4 Ground 5 Rock

Value Type 6 Bug 7 Ghost 8 Steel 9 ??? 10 Fire 11 Water

Value Type 12 Grass 13 Electric 14 Psychic 15 Ice 16 Dragon 17 Dark

If the Pokémon only has one type, both Type 1 and Type 2 will be set to the same value.

Effort yield

Each stat is assigned two bits to determine how many EVs the Pokémon will give in that stat. The last 4 bits in the byte are empty (0).

Bits	Stat
0-1	HP
2-3	Attack
4-5	Defense
6-7	Speed
8-9	Special Attack
10-11	Special Defense

Items

If an item is assigned to Item 1, the Pokémon will have a 50% chance of having that item when encountered in the wild. An item assigned to Item 2 will have a 5% chance of being held. If both Item 1 and Item 2 are the same, then the Pokémon will always be holding that item when it is encountered.

Gender

Main article: Personality value → Gender

This value determines the chance that a Pokémon will be male or female. If the species is not all male, all female, or gender unknown, then this value is compared to the lowest byte of a Pokémon's personality value to determine its gender.

Value	Gender
0	Always male ♂
1-253	Mixed ♂ / ♀
254	Always female ♀
255	Gender unknown

Level-up Type

The following values correspond to the different growth rates a Pokémon can have:

Value	Growth	Lv100 Exp
0	Medium Fast	1,000,000
1	Erratic	600,000
2	Fluctuating	1,640,000
3	Medium Slow	1,059,860
4	Fast	800,000
5	Slow	1,250,000

Egg Groups

The following values correspond to the different Egg Groups a Pokémon can belong to:

Value Type 1 Monster 2 Water 1 3 Bug 4 Flying 5 Field

Value Type 6 Fairy 7 Grass 8 Human-Like 9 Water 3 10 Mineral

Value Type 11 Amorphous 12 Water 2 13 Ditto 14 Dragon 15 No Eggs Discovered

For Pokémon only in a single Egg Group, both entries are the same value.

Safari Zone rate

This value determines the rate at which the Pokémon will flee when encountered in the Safari Zone. Only Pokémon that appear in the Safari Zone have this value set.

Color and Flip

Color is used in the Pokédex's search function in Ruby, Sapphire, and Emerald. The following values correspond to the different possible colors:

Value Type 0 Red 1 Blue 2 Yellow 3 Green 4 Black

Value Type 5 Brown 6 Purple 7 Gray 8 White 9 Pink

"Flip" refers to whether the Pokémon's image is flipped when seen in the summary screen as opposed to when seen in the Pokédex or PC. This is determined by bit 7 (the most significant bit) of this field. For some Pokémon, such as Poliwag, Kingler, and Unown, this bit is set and the image is not flipped (i.e., the image is oriented the same in both places).

Storage

This section is incomplete. Please feel free to edit this section to add missing information and complete it. Reason: Are the Ruby and Sapphire addresses only for US games? For non-US games?

The following are the RAM offsets for the first data entry (Bulbasaur) in each GBA game. Since a game is loaded into RAM at 0x08000000, this means that the offset in a ROM dump will only use the last six hexadecimal digits.

Game	Address
Ruby	0x081FEC34
Sapphire	0x081FEBC4
Emerald	0x082F0D70
EmeraldEN-US	0x083203E8
FireRed	0x082111A8
FireRedEN-US	0x082547A0
LeafGreen	0x08211184
LeafGreenEN-US	0x0825477C

Fingerprint

Below is a sample of the data for the first Pokémon species data structures.

00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  // ?????????? (used for unknown/glitch Pokémon)
2D 31 31 2D 41 41 0C 03 2D 40 00 01 00 00 00 00 1F 14 46 03 01 07 41 00 00 03 00 00  // BULBASAUR
3C 3E 3F 3C 50 50 0C 03 2D 8D 00 05 00 00 00 00 1F 14 46 03 01 07 41 00 00 03 00 00  // IVYSAUR
50 52 53 50 64 64 0C 03 2D D0 00 06 00 00 00 00 1F 14 46 03 01 07 41 00 00 03 00 00  // VENUSAUR
27 34 2B 41 3C 32 0A 0A 2D 41 40 00 00 00 00 00 1F 14 46 03 01 0E 42 00 00 00 00 00  // CHARMANDER
3A 40 3A 50 50 41 0A 0A 2D 8E 40 01 00 00 00 00 1F 14 46 03 01 0E 42 00 00 00 00 00  // CHARMELEON
4E 54 4E 64 6D 55 0A 02 2D D1 00 03 00 00 00 00 1F 14 46 03 01 0E 42 00 00 00 00 00  // CHARIZARD
2C 30 41 2B 32 40 0B 0B 2D 42 10 00 00 00 00 00 1F 14 46 03 01 02 43 00 00 01 00 00  // SQUIRTLE
3B 3F 50 3A 41 50 0B 0B 2D 8F 10 04 00 00 00 00 1F 14 46 03 01 02 43 00 00 01 00 00  // WARTORTLE
4F 53 64 4E 55 69 0B 0B 2D D2 00 0C 00 00 00 00 1F 14 46 03 01 02 43 00 00 01 00 00  // BLASTOISE
...

Data structure in the Pokémon games General Character encoding Generation I Pokémon species • Pokémon • Poké Mart • Character encoding (Stadium) • Save Generation II Pokémon species • Pokémon • Trainer • Character encoding (Stadium • Korean) • Save Generation III Pokémon species (Evolution • Pokédex • Type chart) Pokémon (substructures) • Move • Contest • Contest move • Item Trainer Tower • Battle Frontier • Character encoding (GameCube) • Save Generation IV Pokémon species (Evolution • Learnsets) Pokémon • Save • Character encoding (Wii) Generation V–present Character encoding Generation VIII Save TCG GB and GB2 Character encoding

This data structure article is part of Project Games, a Bulbapedia project that aims to write comprehensive articles on the Pokémon games.