Pokémon data structure (Generation III)

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

Synopsis

• Personality

Controls many things, including sex, unown letter, Spinda's dots, nature, and others.

• Trainer ID

Part of the weak XOR-encryption key in the data section, also used in shiny determination.

• Nickname

The pokemon's nickname, limitted to 10 characters.

• Font

Determines which character set is used for the nickname (?).

• Trainer Name

The name of the trainer whose corresponding ID is in Trainer ID.

• Mark

The marks you see in the storage box. Heart, circle, square, and triangle.

• CRC16

CRC16 value of the 48-byte data section in the middle of the structure. Computed by simply adding all the unencrypted values one word at a time. This value is what makes bad eggs.

• [x]

Any entry marked [x] is not used and usually set to either 0 or -1 of the respective data type.

• [data]

Data section.

• Status

The status byte. A pokemon's status is flagged by the bits:

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

• Level

Single byte indicating level.

• HP Meter

HP remaining.

• HP Total

Maximum HP attainable, your HP stat.

• Attack

Attack stat.

• Defense

Defense stat.

• Speed

Speed stat.

• Special Attack

Special Attack stat.

• Special Defense

Special Defense stat.

Location

A trainer's team starts at the following addresses in the GBA's RAM:

Sapphire: 0x03004360
Ruby: 0x03004360
Fire: 0x02024284
Leaf: 0x020241e4
Emerald: 0x02024190

Six pokemon per team, so the whole team continues for 600 bytes afterward.