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I got factorio through steam ( ) and want to be able to load the game in Vanilla mode or in modded mode.
Is this possible through batch script or similar?
Yes, you can launch factorio with a specific mod directory and/or config file. You can also get info about futher options by simply running factorio.exe --help in any terminal.
If you have many different mod sets and don't want to keep a copy of every mod for every set, you can also use a batch to overwrite mod-list.json prior to startup, which is the file that determines which mods are on/off.