Simple editing of Brood War save files? (.mlx)

gryek

8 Posts

July 26 2025 07:09 GMT

Hi, since stuff like RepMastered, cwal.gg, replay extractors/analyzers etc. exist, I know people out there know some things about how to extract/manipulate the data from Brood War storage file formats. I'd like to edit one simple thing - something about the user id/battletags from multiplayer save (.mlx) files; I assume this can't be too hard. Does anybody have a way how?

In case it helps, the reason I'm asking is because I want to be able to save in custom games vs a friend, and then swap places (like would be possible using SC2's continue from replay feature). I thought I could just send him the .mlx file and have him host it, but it seems like there's something in the file that remembers the account or battletag associated to each player - no matter whether it's me or him hosting the save file, the custom game ends up assigning both of us our original player slots, without an option to switch.

(PS. as a more out-there bonus question, I found that back in the pre-remastered times, someone made a tool called playrep that could save a .mlx file from replay, which would be cool; does anyone know how to do this now?)

LML

Germany1774 Posts

August 06 2025 16:53 GMT

Have you tried anything besides each hosting the save file?

For example, opening the file in a text editor like Notepad++, the save file has a header with human readable information, before showing (likely?) binary code.

Example:

****************************************************
** Starcraft Version 1.23.5.8689
** Multi Player Save Format ver 109.4
****************************************************

Filename: Supermarket Defence.mlx
Players: ImToxicPlayer
Red_LML
Game Type: Use Map Settings
SCM Title: HomePlus Defence 2 v0.13
SCM Path: C:\Users\LML\Documents\StarCraft\Maps\Download\홈플러스_디펜스2[v0.13].scx
EUD Flags: 0

Have you tried something as simple as editing the order under "Players" and saving the file? Is it still usable after? If yes, does that change anything, or do nothing?
Other than that it may be advisable to try and read the byte stream of the file programmatically (idk if maybe a HEX editor could be used). I have no idea about their file format, so these are just blind guesses that could be explored.

edit: after trying those suggestions myself, I couldn't see a difference. I could even load the save file with a different battle.net account (which wasn't part of the saved game) and still host it and be in the 2nd slot, just as before.

gryek

8 Posts

September 04 2025 00:08 GMT

Yeah I tried a lot of this stuff. I tried using zlib to decompress biinary/hex info, and was able to extract some, but it wasn't clean - there's like global header information compressed somehow in a way mysterious to me. I tried swapping the usernames in one decompressed block near the beginning and recompressing, but that broke it. Then kind of gave up.

I've gotten pretty unstable/inconsistent behavior with trying to load the file on an alternate battlenet account on the same machine.

If you (or anyone) figure anything out, I'd love to hear it!

Stopthevirtualaddict

49 Posts

September 04 2025 09:55 GMT

This feels like something you could not do in broodwar.

Please or register to reply.

Simple editing of Brood War save files? (.mlx)

Completed

Ongoing

Upcoming