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The Football Manager (FM) community has always thrived on innovation and customization, and with the advent of FM Tweak's Custom Mods, we would like to introduce you to our Physical Constraints Editor —a tool that makes creating your own custom match engine easier than ever. Whether you want to fine-tune player movement, enhance defensive AI, or introduce more unpredictable physics, this tool allows you to tweak FM24’s match engine mechanics without the need for complex hex editing.
If you do use our tool to create a new match engine, please get in the comments to share what you've created 🙂
Understanding the Match Engine Tweaks
At the core of every FM24 match simulation lies the physical_constraints.jsb file, which determines how players interact with the ball, the pitch, and each other. Traditionally, modifying this file required expertise in using a hex editor, but our Physical Constraints Editor simplifies this process, allowing you to create a custom match engine with ease.
How to Create and Install Your Custom Match Engine
1.Open the Physical Constraints Editor link
- You can upload a custom file to start editing right away
2. Make your Adjustments
- Edit the values under the custom column, you can compare the values you are imputing with other known match engines on the table
3. Download Your Custom File
- Once satisfied with your modifications, click “Download simatch.zip”
How to Install the ZIP file
If you're not sure what you're doing ignore the JSB File and follow the instructions for the ZIP below.
- Click "Download simatch.zip"
- Visit the following location:
- Windows: Program Files (x86)\Steam\SteamApps\common\Football Manager 2024\data\
- Mac: ~/Library/Application Support/Steam/steamapps/common/Football Manager 2024/data
- (For Mac an easy way to access the folder is to open finder and click "Go" > "Go To Folder" then paste the above location.)
- Rename "simatch.fmf" to "simatch.backup"
- Extract the zip so that you have a folder named "simatch" folder.
- Place the "simatch" folder in the above location. If you have another "simatch" folder already delete it.
- Start FM24
- If you ever want to reset back to the original version delete the "simatch" folder and rename "simatch.backup" to "simatch.fmf".
How to Install a custom JSB file
If you really want to use the JSB file for some reason, you'll have to follow these steps
- Extract simatch.fmf (See our resource archiver guide on how to extract fmf files)
- Delete simatch.fmf and place the now extracted “simatch” directory in the same location (these files don’t need to be in .fmf format to work)
- Replace the physical_constraints.jsb in the directory with the one you just downloaded from our editor
If you make future edits to your custom match engine simply visit the physical constraints editor again and use Choose File > Upload Custom File at the top to upload your custom file. That way you don’t need to start from scratch.
And to reinstall your file a second time you only need to do step 3.
Sharing your Custom Match Engine
If you’d like to share your custom match engine you may find it easier to use the resource archiver’s “Create Archive” function to create a new simatch.fmf instead. But you can also just share a zip of the simatch directory. Make sure to instruct anyone you’re sharing it with to remove the original simatch.fmf when using yours and to extract the .zip.
- Date Created
- 18 Mar 2025 18:04:27
- Date Updated
- 01 Apr 2025 21:25:37
- Last Comment
- 18 Apr 2025 04:17:54
Comments
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Awop Ratee
cannot download from button
“Download Modified simatch.zip File” it always error with permission 403
Footygamer
I can't find any issues @Awop Ratee what browser are you using?
alfanso litchmore
when i download the file and put it in the tweak match engine manager and start the game i get a error message and the game does not start.
Are you meant to download a zip folder
or just the file i like the file like how you download it from tweak match engines the zip folder thing has loads of files and confuses me.
Also a guid of how to use the custom engine editor would be useful. as i dont know what half of the parameters mean and how they will affect the game.
But great work regardless