DontDestroyOnLoad issue

In my menu scene I have an empty GameObject that uses DontDestroyOnLoad to maintain variables between scene loads, but every time the menu scene is loaded another copy of it is created and maintained.

I know that I could add code to another script in the menu scene to check and see if the object exists and if it doesn’t instantiate a new one from a prefab, but I have a feeling that there should be functionality built into Unity to do this since the DontDestroyOnLoad function exists in the first place.

There is no such functionality. You can either have a “boot loader scene”, or you can write a simple check inside the Awake method of a “boot loader object”. The following snippet shows how you can create a boot loader that instantiates an object if it hasn’t already been instantiated. If you then make this BootLoader a prefab and have it in each scene, then you can rest assured that you will always get a prefab instantiated once. This prefab the boot loader instantiates could then hold your data.

public class BootLoader : MonoBehavior {
    public GameObject prefab;
    static Object instance;
    void Awake () {
        if (!instance) { 
            instance = Instantiate (prefab);
            DontDestroyOnLoad (instance);
        DestroyImmediate (gameObject);