Breath of Fire II:ROM map
The following ROM data was obtained from an old Gamefaqs thread (link) by a user called StarryKnights.
Characters starting information
Initial data for the game's characters. Information block starts at x00:087C ($C0:087C) and ends at x00:0D3B ($C0:0D3B) (Assuming no header). Each entry is 64 bytes long. This data follows the RAM PC data setup from the RAM map, though, much of this start up data goes unused. Layout: 01-04: Character Name 05: Unused (In-game compared to RAM, setting this value to 20 would make the PC sprite into Valerie) 06: Unused (PC Status) 07: Character's PC Number 00 - Ryu 01 - Bow 02 - Rand 03 - Katt 04 - Nina 05 - Jean 06 - Sten 07 - Spar 08 - Bleu 09 - Kid Ryu 0A - Kid Bosch (Zombie in battle) 8: Initial level 9-10: Unused (Current health) 11-12: Initial HP 13-14: Unused (Current AP) 15-16: Initial AP 17: Shaman Form 18: Initial Strength 19: Initial Stamina 20-21: Initial Agility 22: Initial Condition 23-24: Initial Weapon (Value 11 tells the game that you have a weapon equipped) 25-26: Initial Shield (Value 21 tells the game that you have a piece of armor equipped) 27-28: Initial Armor (Value 21 tells the game that you have a piece of armor equipped) 29-30: Initial Helmet(Value 21 tells the game that you have a piece of armor equipped) 31-32: Initial Accessory 1 (Although set to 00 00 on most characters, this is bugged as you're not supposed to be able to unequip 'nothing') 33-34: Initial Accessory 2 (Although set to 00 00 on most characters, this is bugged as you're not supposed to be able to unequip 'nothing') 35-36: Unused (Current Attack) 37-38: Unused (Current Defense) 39-40: Unused (Current Vigor) 41: Unused (Current Wisdom) 42-43: Unused (Current Luck) 44: Initial Guts 45: Initial Wisdom Base 46: Initial Luck Base 47-49: Initial EXP 50-64: Unused There are three sets of characters in this data block. The first set is for the normal game, for the most part. The second set consists solely of Child Ryu and Child Bow. Adult Ryu (Maybe Adult Bow too) inherits his stats from Child Ryu. This is only worth noting if you want to change his starting stats. The third set is what I can only surmise are the team's stats during the title screen demos.
Stat gain tables
Stat Gain Tables: ---- Hex offset (LoROM Address) x05:71B0 - x05:5DEF ($C5:71B0 - $C5:5DEF) 4 bytes, split into 8 half-bytes in this order with a max increase of '15 (F)' per stat: Byte 1: HP, AP Byte 2: Strength, Stamina Byte 3: Unused, Agility Byte 4: Wisdom, Luck Almost every character seems to have extra level gains for levels they don't join at. These are not used at all due to the initial data. <br/>Also, it seems Bleu's stats uses the Monster Table as her level up data so she doesn't have her 'own' to modify without some serious stat table moving. Guts gain upon level is consistently the same for every level up. Each PC's gain starts at: x01:8FE5 ($81:8FE5)
Enemy stats: 59000-5A8FF Bytes 1-8: Name 9-10: Hit points 11-12: AP 13: Luck 14-15: Attack 16-17: Defense 18-19: Agility 20: Drop rate??? 21-22: Experience 23-24: Zenny 25: Item set 26-32: Unknown
For detailed information on how drop rates and item sets work, check out Ben Siron's handbook that explains many of the game's mechanics: link
Spell gains table
Pointers: 5AA00-5AA011 5AA12-5AADE Pairs of bytes. First is for level the spell is gained on, the second is the spell gained. 00 terminates.