Mod class functions explained - piotrulos/MSCModLoader GitHub Wiki

OnMenuLoad()

Executed when game loads Main Menu. When this function is declared via SetupFunction OnGUI(), Update() and FixedUpdate() will also be called in Main Menu.

OnNewGame()

Executed when creating a New Game, you can delete your mod's save file here.

PreLoad()

Executed once right after "Now loading year 1995..." screen. It's also before game is fully loaded, used when OnLoad() is too late for you.

OnLoad()

Executed once after game is fully loaded (First frame when you can control character).

PostLoad()

Executed once after all mods OnLoad() was called, used for late loading or when you want to make your mod compatible with other mod.

OnSave()

Executed when game is saved. You can save your mod here.

OnGUI()

Standard Unity OnGUI function. https://docs.unity3d.com/500/Documentation/Manual/GUIScriptingGuide.html

Update()

Standard unity Update. Executed each frame. if you are using OnMenuLoad() you can do GetCurrentScene check to execute something in Menu and something in Game.

FixedUpdate()

Standard unity FixedUpdate.