SNES Development
Seiken Densetsu 3 SRAM Format

Open your saveram file in your hex editor. Seiken Densetsu 3 has three save logs; each one takes up 0x800 bytes. The first 0x70 bytes, from 00 to 6F, are a kind of header – it’s the info that appears on the save / load screen, and has no effect on your actual game.

All addresses in this document will be for log 1; if you want to hack log 2, add 0x800; if you want to hack log 3, add 0x1000. For example, maximum MP for character 1, log 1 is at 0x1FF. Max MP for character 1, log 2 is at 0x9FF. Speaking of maximum MP, let’s hack that right now, so you can get the hang of hacking Remember, values are always in reverse byte order.

Checksum

A checksum is the sum of all bytes in a file (or a certain part of it) that’s used to check for file integrity. When you save your game, Seiken Densetsu 3 adds up all the bytes in your save log and writes that 2-byte sum at the end of your save log. When you come back to the game, it adds up all the bytes in the save log again and compares that to the stored checksum. If those two sums don’t match, Seiken Densetsu 3 assumes that the save log is corrupt (maybe the battery failed or something) or doesn’t exist.

This is a problem when you want to hack your saved game, because if you change the data without changing the checksum appropriately, Seiken Densetsu 3 will think the log is corrupt, and you’ll get the dreaded “No Save File.” When you’re making only small changes, like you did in the Quick Start section, it’s easy to fix the checksum, but if you make a lot of big changes, it’ll be a lot easier to just recalculate the checksum. Hex Workshop has an easy way to do this. If you’re using something else, it’s up to you to figure out.

To calculate the checksum we will simply add all the bytes, excluding the last 2, in a log together, a simple Checksum 16. Select the proper block of data. The first 0x70 bytes of each save log are a kind of header and aren’t included in the checksum. Start at 0x70 and select all the way down through 0x7FD. This is a total of 0x78E bytes for log 1. If this is a working save log you’re looking at, the checksum you’ve calculated will be the same as the 2-byte value at 0x7FE of your saveram.

After you finish making all your changes to your save file, you need to fix the checksum before you can play it. Follow the above procedure. Take the value you’ve calculated and write it over the old checksum at 0x7FE.

General Stats

I don’t know exactly where each character’s data block begins and ends. For the first character, the first value I know is current HP at 0x172-0x173, and the last value I know is maximum MP at 0x1FF-0x200. I do know that each character’s data takes up 0xFF bytes.

Important: All these following addresses will be for the first character’s data. If you want to hack the second character’s data, add 0xFF to the address. If you want to hack the third character, add 0x1FE. For instance, character one’s current HP is at 0x172-0x173; character two’s is at 0x271-0x272, and character three’s is at 0x370-0x371.

Attack, Evade, Defense and Magic Defense are determined by your stats and equipment, so any changes to these won’t be permanent.

Equipment

Weapons

A value of 0x00 is Nothing. 0x01-0x1E are Swords. 0x1F-0x2A are cool-looking "Nothing" swords with varying attack power. Each character's weapons take up 0x2A values: 0x01 is the first sword, 0x2B is the first glove, 0x55 is the first dagger, 0x7F is the first rod, 0xA9 is the first flail, and 0xD3 is the first spear. Sorry, no matter what weapon a character is equipped with, they'll look and fight the same as ever.

Armor, Helmets, Rings & Shields

0x00 is Nothing. 0x01-0x48 are helmets; each character takes up 0x0C values. 0x49-0x7E are rings; each character takes up 0x09 values. 0x7F-0xF6 are armor; each character takes up 0x14 values. 0xF7-0xFF are all shields! (I wonder if they’re all available in the actual game.) Notice that you can put any armor type in any spot, which can lead to strange stats.

Magic

Detect was apparently dummied out and has no description or effect. Second and Third Level Power Attacks you can “cast” for 0 MP, though be warned that if the “wrong” character uses an attack, it’ll look funny at best, and crash the game at worst. Enemies’ Special Attacks (and trap effects, etc.); like character techs, they don’t consume any MP. Most “SBD’s” are just visual effects.

Spell Targeting has a valid range between 0x01 and 0x04: 01 is One, 02 is All, 03 is One/All, and 04 is caster (for ally-targeted spells) or last ally targeted (for enemy-targeted spells).

Class

Class family is a value from 00 to 05, with 00 being the Fighter classes, 01 being the Grappler classes, and so on. Class changes is 00 for the base class, 01 for a second-level class, and 02 for a third-level class. Light-dark scale can range between 00 and 03, with 00 being light-light and 03 being dark-dark.

Party Data

Item Ring

0x00 is Nothing. 0x01-0x18 are third-level class items. 0x19-0x1E are seeds. 0x1F-0x4E are magic items; these are arranged just like the spells they correspond to. 0x4F-0x52 are thrown weapons. 0x53-0x59 are recovery items. 0x5A-0x66 are special items, quest items, and dummied items (including 5A Magical Rope and 60 Dreamsee Herb). 0x67 on are Nothings.

Storage

This long list corresponds to the values that are used on your item ring. That is, 0x6A5 is how many Nothings you have in storage, 0x6A6 is how many Paladin Proofs, etc. A value of 0x00 means you don’t have that item in storage, obviously. If you set all of these values to 0x01, you’ll have one of every item in storage.

Originally written by Jair from the Vale, expanded up and corrected by various others.