Unity IL2CPP vs Mono

In traditional Unity games, C# code compiles into CIL bytecode and runs on the Mono runtime. In IL2CPP (Intermediate Language To C++), Unity converts all C# code into native C++ code and compiles it into a native binary (GameAssembly.dll).

To write mods for IL2CPP games in C#, we use BepInEx 6 IL2CPP together with Il2CppInterop / Unhollower, which creates managed C# wrapper classes that interface directly with the native Il2Cpp domain.