What BepInEx is and why you need it

BepInEx is a modding framework — a piece of software that sits between your game and the mods you want to run. It loads mods into the game when the game starts, handles conflicts between mods, and gives mod creators the tools to change how the game works. Without it, most mods for Unity-based games simply will not run.

Think of it like an adapter. The game expects to load certain files in a certain order. BepInEx intercepts that process, inserts the mods you want, and lets everything load together. Different games need different versions of BepInEx — the one for Valheim is not the same as the one for Risk of Rain 2 — so you will need to download the right build for your specific game.

The installation itself is straightforward: download the correct version, extract it into your game folder, run the game once, and the framework sets itself up. Most of the confusion comes from finding the right version and the right game folder, not from the installation steps themselves.

Key Takeaways

  • Download BepInEx from the official GitHub releases page, choosing the version that matches both your game and your operating system (Windows, Linux, or Mac).
  • Extract the BepInEx files directly into your game's root folder — the same folder where the game's executable file (.exe) sits.
  • Launch the game once after extraction; BepInEx will create its own folders and configuration files automatically on that first run.
  • After the first launch, place mod files into the BepInEx/plugins folder, then restart the game to load them.
  • If mods do not load, check the BepInEx/LogOutput.log file to see what went wrong — the error messages there tell you whether a mod is incompatible, missing a dependency, or corrupted.

Finding your game folder and the correct BepInEx version

Locate your game folder first. On Steam, right-click the game in your library, select Properties, then Local Files, then Browse. That folder is where you will extract BepInEx. On Epic Games, the process is similar: right-click the game, select Manage, then Open Folder. If you own the game outside Steam or Epic, navigate to wherever you installed it.

Next, go to the BepInEx GitHub releases page at github.com/BepInEx/BepInEx/releases. You will see a list of versions. Each release has multiple downloads — one for Windows x64 (64-bit Windows), one for Windows x86 (32-bit Windows), one for Linux, and one for Mac. Download the one that matches your operating system. Most modern games run on 64-bit Windows, so BepInEx_x64 is the most common choice. If you are unsure whether your Windows is 32-bit or 64-bit, open Settings, go to System, then About, and look for "System type" — it will say either 64-bit or 32-bit.

The version number (like 5.4.21) matters less than the operating system. Newer versions are generally better, but if a mod guide tells you to use a specific version, follow that instruction — some older games have compatibility issues with the latest BepInEx.

Extracting BepInEx into your game folder

Once you have downloaded the BepInEx .zip file, extract it. On Windows, right-click the file and select Extract All, then choose your game folder as the destination. On Mac or Linux, double-click the .zip or use the command line to unzip it into the game folder. The extraction will create a BepInEx folder, a doorstop_config.ini file, and a few other files directly inside your game folder.

This is the most common mistake: people extract BepInEx into a subfolder by accident. You should see the BepInEx folder sitting right next to your game's executable file (.exe on Windows), not nested inside another folder. If you extracted it wrong, move the BepInEx folder up one level so it is at the same depth as the game executable.

After extraction, your game folder should look like this: the game executable, the BepInEx folder, doorstop_config.ini, and possibly a few other game files. If you see a folder called BepInEx/BepInEx, you extracted it one level too deep — move the inner BepInEx folder up.

Running the game to initialize BepInEx

Launch the game normally through Steam, Epic, or however you usually start it. Let it run for at least 30 seconds, then close it. During that first run, BepInEx creates its internal folder structure: BepInEx/plugins (where mods go), BepInEx/config (where mod settings live), and BepInEx/LogOutput.log (where errors are recorded).

Do not panic if the game crashes on the first launch. Some games have compatibility issues with BepInEx, and the crash log will tell you why. Check the BepInEx/LogOutput.log file — open it with Notepad or any text editor. If you see a message like "Failed to load" or "DLL not found," that is a sign that either BepInEx is not compatible with your game version, or you extracted it into the wrong folder.

If the game launches and closes normally, BepInEx is working. You are ready to add mods.

Installing mods into BepInEx

Mods for BepInEx come as .dll files or as folders containing .dll files. Download the mod from its source — usually Nexus Mods, GitHub, or the game's community mod site. Read the mod's instructions; some mods go directly into BepInEx/plugins, while others need to be placed in a subfolder.

Most commonly, you will extract the mod's .zip file and drag the .dll file (or the entire mod folder) into BepInEx/plugins. Then restart the game. BepInEx will load the mod on startup. If the mod does not appear or does not work, check BepInEx/LogOutput.log for error messages. Common errors include a missing dependency (another mod the first mod needs to run), a version mismatch (the mod was built for a different game version), or a corrupted download.

If multiple mods conflict, the LogOutput.log will usually tell you which one failed to load. Disable the conflicting mod by moving it out of the plugins folder, restart the game, and check if the other mods work. Then research whether the two mods are known to conflict, or whether one needs to load before the other.

Troubleshooting common installation problems

If BepInEx does not load at all, the most likely cause is that you extracted it into the wrong folder. Double-check that the BepInEx folder is at the same level as the game executable, not nested inside another folder. Also verify that you downloaded the correct version for your operating system — a Windows x64 build will not work on a 32-bit system, and a Windows build will not work on Mac or Linux.

If the game crashes immediately after you add a mod, that mod is either incompatible with your game version or missing a dependency. Remove the mod from BepInEx/plugins, restart the game, and check if it runs. If it does, the mod is the problem. Read the mod's description again — it may require a specific game version or another mod to be installed first.

If you see a message like "BepInEx not found" or the game loads without BepInEx running, the doorstop_config.ini file may be missing or corrupted. Re-extract BepInEx into your game folder, making sure all files are in place. On some games, you may also need to run the game as Administrator (right-click the executable, select Run as Administrator) for BepInEx to initialize properly.

Uninstalling BepInEx if you need to

To remove BepInEx, delete the BepInEx folder and the doorstop_config.ini file from your game folder. That is all. The game will run normally without them. If you want to keep your mod settings or configuration files, back up the BepInEx folder before deleting it.

Some games may need to be verified through Steam or Epic after you remove BepInEx, especially if the game's files were modified. Right-click the game in Steam, select Properties, Local Files, then Verify Integrity of Game Files. This will re-download any files that BepInEx or mods changed, restoring the game to its original state.

Frequently Asked Questions

How do I know if my game uses Unity and supports BepInEx?

Most indie games and many AAA games run on Unity. If you are unsure, search "[game name] BepInEx" — if other people have made mods for it using BepInEx, your game supports it. You can also check the game's store page; it often lists the engine. If the game uses Unreal Engine or a proprietary engine, BepInEx will not work.

Do I need to disable mods before updating the game?

Not always, but it is safer to do so. Move the mods out of BepInEx/plugins, update the game through Steam or Epic, then move the mods back. This prevents the game from trying to load mods that may be incompatible with the new version. After the update, check the mod creator's page to see if they have released a new version of the mod for the updated game.

Can I use BepInEx on a pirated or cracked game?

Technically yes, but it is not recommended. Cracked games often have modified files that conflict with BepInEx, and you will not receive updates that fix compatibility issues. If you own the game, use the official version from Steam, Epic, or another legitimate store.

What if two mods want to modify the same game file?

That is a conflict. Check the mod descriptions to see if the creators have documented a load order or a known incompatibility. Some mod managers (like r2modman) handle load order automatically. If the mods are truly incompatible, you will have to choose one or the other.

Why does my antivirus flag BepInEx as a threat?

BepInEx modifies how the game loads, which some antivirus software interprets as suspicious. It is a false positive — BepInEx is open-source and widely used. Add BepInEx to your antivirus whitelist, or temporarily disable the antivirus during installation. If you are uncomfortable doing that, you can review the BepInEx source code on GitHub to verify it is safe.