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Pokédex data structure in Generation III

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A Pokédex data structure is a 36-byte (32-byte for Pokémon Emerald) piece of data.

Every Pokémon species in the Generation III games has data stored in the game that is used in Pokédex related functions and by certain moves, such as Low Kick.

Pokédex Data
Name 12 bytes
Height (10-1 m) 2 bytes
Weight (10-1 kg) 2 bytes
Description pointer #1 4 bytes (See Notes)
Description pointer #2 4 bytes (See Notes)
Pokémon scale 2 bytes
Pokémon offset 2 bytes
Trainer scale 2 bytes
Trainer offset 2 bytes


  • Name is 12 bytes long and comes in capital letters. 0x00 fills possible empty bytes. This is the species name and not the Pokémon name ("SEED" instead of "BULBASAUR").
  • Height is measured in decimeters (10-1 meters), and is then converted to other units in specific versions of games.
  • Weight is measured comes in hectograms (10-1 kilograms), and is then converted to other units in specific versions of games.
  • Description pointers show the game where the description for the particular Pokémon is. The GBA is Little Endian, and that a ROM file is loaded at an offset of 0x08000000.
Ruby, Sapphire, FireRed and LeafGreen have two pages of text while Emerald has only one-- "Description pointer #2" simply does not exist.
  • Pokémon offset is a signed 16-bit integer; therefore, if the raw value is 0x8000 or greater, then it is negative, with 0x8000 as -32,768 and 0xFFFF as -1.

Size compare function

In Generation III, there is a size page on the Pokédex, which uses data from the Pokédex to create a silhouette of the Pokémon standing next to the Trainer. The size of both the Trainer and Pokémon are determined by this formula:

x = (y × 256/z) pixels

Where y is the sprite size (64 pixels in this case) and z is the appropriate scale in hex and x rounded down is the size of silhouette. The game then resizes the sprite in a way similar a computer would do (without anti-aliasing).

The offset determines where exactly the silhouette will be placed. For example if Pokémon offset = 10 then the silhouette of the Pokémon will be 10 pixels from the top and 10 pixels from the left. (For some reason, that cannot be exactly simulated outside of the game).


Ruby: 0x083B1858
Sapphire: 0x083B18B0
Emerald: 0x0856B5B0
FireRed: 0x0844E850
LeafGreen: 0x0844E270

Data structure in the Pokémon games
Generation I Pokémon data structurePokémon base stats data structureSave data structure
Generation II Pokémon data structurePokémon base stats data structureTrainer data structureSave data structure
Generation III Pokémon data structurePokémon data substructuresPokémon base stats data structureMove data structure
Contest data structureContest move data structureItem data structurePokédex data structureBattle Frontier data structures
Trainer Tower data structuresPokémon evolution data structureType Chart data structureSave data structure
Generation IV Pokémon data structureSave data structure

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