Resetting Runtime Data After Play Mode

In this lesson, you will learn how to prevent persistent changes in your ScriptableObject assets from carrying over between Play Mode sessions.

When you modify a ScriptableObject variable during Play Mode, Unity treats that change as part of the asset itself. Because these assets live in your Project folder and exist outside of the scene hierarchy, those changes don't automatically reset when you hit the "Stop" button. If you accidentally leave a player’s health at 0 or keep a "Level Unlocked" flag active, your next play session will start with corrupted or unexpected data.

To solve this, we use a simple "Reset Pattern" within an OnEnable method. By ensuring that your data resets whenever the script is loaded or the game begins, you ensure a clean slate every time.

Implementing the Reset Pattern

The most effective way to handle this is to define your default values in a specific method and call it when the game starts. Here is how you can structure a data-holding ScriptableObject:

using UnityEngine;

[CreateAssetMenu]
public class GameData : ScriptableObject
{
    public int currentScore;
    public bool isGameOver;

    // Define the default state here
    public void ResetToDefaults()
    {
        currentScore = 0;
        isGameOver = false;
    }

    private void OnEnable()
    {
        // Automatically reset data when the asset is loaded
        ResetToDefaults();
    }
}

By adding OnEnable, you ensure that the ScriptableObject re-initializes its values the moment the project compiles or the game enters Play Mode. This acts as a safety net, guaranteeing that your game state doesn't "remember" the chaos from your previous testing session.

Another approach is to manually call ResetToDefaults() inside the Start() method of a global manager script. This is particularly useful if you want to control exactly when the reset occurs, such as only when the main menu loads. Regardless of the method you choose, the goal is always the same: treat your assets as templates and your runtime values as temporary overrides that get wiped clean before the next session begins.

Key Takeaway: Because ScriptableObjects persist outside of the scene, you must explicitly implement a reset method to ensure your game logic always starts from a predictable default state.