FM24 Match Physics Mod: Asian Fusion

Brief History

A reddit post towards the end of January 2025 by EvensenFM got the attention of several FM enthusiasts as it raised awareness about an update to FM24's physics engine created by a Chinese FM player (红骑士Sakura).
This second version of the Chinese mod provides the most noticeable visual effects, making gameplay animations smoother and more enjoyable to watch. However, it caused slightly unrealistic results, increasing the total number of goals per season by around 10-20 per team.

Another reddit post (again by EvensenFM) shed light on another ME mod which has been in the making since December 2024. The folks over at FM Korea (linked page requires a member account there to access) came up with their own version of the simatch file.
This Korean mod alters many more parameters but with much subtler changes, making them almost imperceptible visually. It feels like having a bit more realistic defensive plays.

FrancescoMuja analyzed these 2 match engine physics mods and combined the v2 of Chinese mod and the Korean mod into a single mod that's known as Asian Fusion or Asian Mix. The results from simulating a season with this mod are very similar to those obtained with the Chinese mod, but as if it had been slightly toned down.

A community effort for an even better ME mod

A group of people actively conversing on reddit about the gameplay changes caused by these mods formed a team coordinated by Head_Championship917 aiming to create the best simatch file we can possibly have. You can join their discord server to share your feedback in an organised way to improve this further.
Discord: FM TWEAK
We all love FM, and with FM25 cancelled there's a need for this kind of community work to fresh things up. The FM TWEAK team launched today a dedicated website where they're presenting the results of their work, by providing different 'flavours' of ME files.

How to install the match physics mod on FM24

1. Back up your original simatch.fmf file. This is really important. Make a copy of it in some other directory and remember where it is. If something screws up, you can always go back to it.
   
2. Locate your data directory. This exists whether you run the game on Windows, Mac, or Linux through Proton. It is not the same directory that your graphics and editor data files go in. You'll know you've found the right directory because it will be called "data" and will have a bunch of FMF files - simatch.fmf, simatchshared.fmf, simatchviewer.fmf and so on.
   
3. Copy this version of simatch.fmf over the existing one in that directory. You don't need to use the Resource Archiver tool unless you are trying to combine this with other patches that impact simatch.fmf (such as the MetzFM sound pack).
   
4. Share feedback on how this version works. Once you get it working, play some games and let everyone know how this works. Let's get some community feedback going and see if we can turn FM24 into the game it should have been all along.
   

Donations

If you wish to support the FM TWEAK team, you can donate using the link below.
Buy a coffee

How to edit the physical_constraints file

This is strictly about changing the physics of the match engine. If you'd like to try fiddling with that yourself, Francesco explained the process.

1. Extract the simatch.fmf file with the Resource Archiver tool.
   
2. Open the physical_constraints file with a HEX editor (e.g. HEX Fiend), which allows you to read the file in both HEX and ASCII formats. Each parameter is easily readable in ASCII, and in HEX format, right after the parameter name, there is a byte 02 (which acts as a "separator"), followed by a 4-byte little-endian value—that’s the value that can be modified.
   
3. Once the modifications are completed, re-archive everything with the Resource Archiver tool and replace the file in the corresponding directory.
   

Credits

This version of simatch.fmf was created by FrancescoMuja who is part of the FM TWEAK team.
Website @fmtweakupdates
Thanks to FrancescoMuja, EvensenFM and Head_Championship917 for their communication and for making it possible to share these physics mods here.