Pokémon data structure (Generation III)

Pokémon in the games Ruby, Sapphire, FireRed, LeafGreen, and Emerald are all stored the same way in a 100-byte structure.

Notes

Pokémon
	type	offset
Personality	dword	0
OT ID	dword	4
Nickname	10 bytes	8
Font	byte	18
Sanity byte?	byte	19
OT name	7 bytes	20
Mark	byte	27
Checksum	word	28
????	word	30
Data	48 bytes	32
Status ailment	dword	80
Level	byte	84
????	byte	85
Current HP	word	86
Total HP	word	88
Attack	word	90
Defense	word	92
Speed	word	94
Sp. Attack	word	96
Sp. Defense	word	98

Personality value

The personality value controls many things, including gender, Unown letter, Spinda's dots, nature, and others.

OT ID

The Original Trainer's ID Number. Part of the XOR encryption key for the data section, also used in shiny determination and the lottery.

Nickname

The Pokémon's nickname, limited to 10 characters. Use the Pokéscii Table to convert to readable characters.

Font

Determines which character set is used for the nickname (?). This is used to determine what colour should be used to write nicknames in a Pokémon's status screen. They may appear in either blue (boy) or pink (girl).

OT name

The name of the original trainer of the Pokémon.

Mark

The marks seen in the storage box. These marks serve only to aide in organizing large collections of Pokémon.

float

Bit	Mark
0	Circle
1	Square
2	Triangle
3	Heart

Checksum

The checksum is of the 48-byte data section in the structure. It is computed by simply adding all the unencrypted values one word at a time. If this value does not match the real checksum, the Pokémon is interpreted as a Bad egg.

Padding

Any entry marked (Padding) is not used and usually set to either 0 or -1 of the respective data type.

Status ailment

The Pokémon's status ailments are stored as follows:

0-2: Sleep bits. Indicates turns of sleep, so 111b = 7 turns, 101b = 5 turns, etc.
3: Poison
4: Burned
5: Frozen
6: Paralysis
7: Bad poison

Location

A trainer's team starts at the following addresses in the GBA's RAM (for US games?):

• Ruby: 0x03004360
• Sapphire: 0x03004360
• Emerald: 0x02024190 (0x020244EC for US games??)
• FireRed: 0x02024284
• LeafGreen: 0x020241e4

There are 6 Pokémon per team, so the whole team continues for 600 bytes afterward.

This structure is used to save data on Pokémon stored in your team. The structure for Pokémon saved in the PC stops after the data field, making it only 80 bytes long.
This explains why Pokémon injured by status ailment will cure themselves when put in the PC. It also applies to stats and level, which are recalculated based on Experience.
Thus, there are also 33600 (14*30*80) bytes stored somewhere else in the GBA's RAM to save data on Pokémon in the PC.

When the VBA's saved state (including memory contents) are ungzip'ed into a 740,000+ byte file and viewed, the 14 boxes of 420 Pokémon are stored in the general region of $038000 $040000.