Battle Frontier data structures (Generation III)

There are a number of data structures in the Pokémon Emerald game ROM that govern the Battle Frontier and the Battle Tents. These are outlined below.

All memory addresses refer to the addresses used in the US version of the game.

Opposing Trainers

The Battle Frontier contains a master list of 300 opposing Pokémon Trainers that may be chosen as an opponent in battle; these are generally sorted in increasing order of difficulty. Similarly, each of the Battle Tents has a smaller list of Trainers: 70 for the Slateport Battle Tent and 30 for the Verdanturf and Fallarbor Battle Tents. Trainer data is stored as a 52-byte structure, outlined as follows:

Size Type Description
4 uint32_t Trainer class
8 char[8] Name
12 Easy Chat structure[6] Challenge Quote - the quote given before battling the opposing Trainer. This is a phrase constructed using the easy chat system.
12 Easy Chat structure[6] Win Quote - the quote given when you lose against the opposing Trainer.
12 Easy Chat structure[6] Lose Quote - the quote given when you win against the opposing Trainer.
4 uint16_t* Pokémon Used - the pointer points to an 0xFFFF-terminated array of indices in the list of opposing Pokémon. Note that not all Pokémon in the list may be used in all Battle Frontier facilities.

The lists of Pokémon used appear immediately before the list of opposing Trainers for each facility. Note that the range of Trainers that will be used in any facility will be dependent on the current winning streak at that facility.

The list of Trainers appear at memory addresses 0x085D5ACC for the Battle Frontier, 0x085DDA14 for the Slateport Battle Tent, 0x085DE610 for the Verdanturf Battle Tent, and 0x085DF084 for the Fallarbor Battle Tent.

Opposing Pokémon

The Battle Frontier contains a master list of 882 opposing Pokémon, again in general order of increasing difficulty. The list of opposing Pokémon is only 70 for the Slateport Battle Tent and 45 for the Verdanturf and Fallarbor Battle Tents. Pokémon data is stored as a 13-byte data structure (aligned on 4-byte boundaries, for a total of 16 bytes), outlined as follows:

Size Type Description
2 uint16_t Species ID - see List of Pokémon by index number (Generation III) for the list of values and their associated Pokémon.
8 uint16_t[4] Moves - see List of moves for the list of values and their associated move.
1 uint8_t Held Item - these are not item indices, rather indices to a separate list of item indices, see below
1 uint8_t EV spread - bitfield, see below
1 uint8_t Nature

Note that all other information needed to generate the Pokémon itself (such as IVs) will depend on the facility and current winning streak therein.

The list of Pokémon appear immediately after their corresponding list of Trainers in memory: the Battle Frontier list is located at address 0x085D97BC, the Slateport Battle Tent list is located at 0x085DE02C, the Verdanturf Battle Tent list is located at 0x085DEC28, and the Fallarbor Battle Tent list is located at 0x085DF96C.

Held item

For the Battle Frontier facilities, a separate list of 63 values (indices to the master item list) is used to denote items. This list may be located at memory location 0x085CECB0. For convenience, it is reproduced here.

0 1 2 3 4 5 6 7 8 9 A B C D E F
0 Nothing King's Rock Sitrus Berry Oran Berry Chesto Berry Hard Stone Focus Band Persim Berry Miracle Seed (Berry Juice) Macho Brace SilverPowder Cheri Berry BlackGlasses Black Belt (Soul Dew)
1 Choice Band Magnet Silk Scarf White Herb DeepSeaScale (DeepSeaTooth) Mystic Water Sharp Beak Quick Claw Leftovers Rawst Berry Light Ball Poison Barb NeverMeltIce Aspear Berry Spell Tag
2 BrightPowder Leppa Berry Scope Lens TwistedSpoon Metal Coat Mental Herb Charcoal Pecha Berry Soft Sand Lum Berry Dragon Scale Dragon Fang Iapapa Berry Wiki Berry Sea Incense Shell Bell
3 Salac Berry (Lansat Berry) Apicot Berry (Starf Berry) Liechi Berry Stick Lax Incense Aguav Berry Figy Berry Thick Club Mago Berry Metal Powder Petaya Berry (Lucky Punch) Ganlon Berry

Item names in parentheses are not used on any Pokémon in the Pokémon lists.

EV spreads

EV spreads are stored in a six-bit bitfield:

--xxxxxx EV spread
-------1 HP
------1- Attack
-----1-- Defense
----1--- Speed
---1---- Special Attack
--1----- Special Defense

The 510 EVs will be divided evenly among all stats whose bit are set. (Since 510 is not divisible by 4, a Pokémon whose EVs are spread across 4 stats will only have 508 EVs.)

Wild Pokémon in the Battle Pyramid

Wild Pokémon in the Battle Pyramid are stored in a 12-byte structure, as follows:

Size Type Description
2 uint16_t Species ID - see List of Pokémon by index number (Generation III) for the list of values and their associated Pokémon.
1 uint8_t Base level - increased or decreased randomly by up to 5 on each wild Pokémon encountered
1 uint8_t Unknown - seems to always be 2
8 uint16_t[4] Moves - see List of moves for the list of values and their associated move.

Mind ratings

In the Battle Arena, each move is given a Mind rating. Over the course of the battle, each move used will contribute its Mind rating to the Trainer's mind score; the player with the higher rating wins the 2 points in overall judgment. Mind ratings are stored as an array of 355 (the number of move IDs in the game) signed 8-bit integers at memory location 0x08611DC0; normally, these range from -1 to 1.

To access the Mind rating for any particular move, take the corresponding index in this array.

Battle style moves

In determining a Trainer's battle style in the Battle Factory and Battle Dome, seven lists of moves are kept by the game, and from these, one of nine battle styles is determined. The Trainer's Pokémon's moves are matched up against these seven lists, and a list is considered "satisfied" if the Trainer has enough moves from that list. The number of moves that are needed for a list to be satisfied is stored in memory location 0x08611FC0 as a list of 7 unsigned 8-bit integers; by default this is three moves for the first three lasts and two for the last four. The game then determines the battle style based on how many of the lists are satisfied (either none, 1-2, or at least 3; the middle one of which will also state the last list that was satisfied, for a total of 9 styles).

The master list of moves used in determining battle style is stored as an array of 7 pointers to lists of 16-bit unsigned integers, referring to the corresponding indices in the master move list (see List of moves). All seven lists have no fixed length, and are terminated with 0x0000.

Address Battle Style
0x08611FC8 "... one based on total preparation"
0x08611FCC "... slow and steady"
0x08611FD0 "... one of endurance"
0x08611FD4 "... high risk, high return"
0x08611FD8 "... weakening the foe to start"
0x08611FDC "... impossible to predict"
0x08611FE0 "... depend on the battle's flow"

The lists of moves appear immediately before the seven pointers themselves in the game ROM. The number of moves needed to satisfy each list appears immediately before the lists of moves.

Data structure in the Pokémon games
Generation I Pokémon speciesPokémonPoké MartCharacter encodingSave
Generation II Pokémon speciesPokémonTrainerCharacter encoding (Korean) • Save
Generation III Pokémon species (Pokémon evolutionPokédexType chart)
Pokémon (substructures) • MoveContestContest moveItem
Trainer TowerBattle FrontierCharacter encodingSave
Generation IV PokémonSaveCharacter encoding
Generation V-present Character encoding
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.