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*	Pokemon Used - the pointer points to an 0xFFFF-terminated array of indices in the list of opposing Pokemon. Note that not all Pokemon 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).
8	uint16_t[4]	Moves - see List of moves.
1	uint8_t	Held Item - these are not item indices, rather indices to a separate list of item indices
1	uint8_t	EV spread - bitfield, see below
1	uint8_t	Nature

Note that all other information needed to generate the Pokemon 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.

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 judgement. Mind ratings are stored as an array of 355 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, 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 (this is three moves for the first four lists and two moves for the last three). 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.