Why DontDestroyOnLoad usage in Unity? - Purpose & Use Cases

The Big Idea

What if your game's music and score could magically survive every scene change without extra code?

The Scenario

Imagine you are making a game where the player's score or music should keep playing even when moving between different game levels or scenes.

Without special handling, every time you load a new scene, all objects from the previous scene disappear, and you lose the score or music.

The Problem

Manually copying data or restarting music every time a new scene loads is slow and error-prone.

You might forget to save or restore something, causing bugs or a bad player experience.

The Solution

DontDestroyOnLoad lets you mark important game objects so they stay alive and keep working across scene changes automatically.

This means your music keeps playing and your score stays intact without extra work.

Before vs After

✗ Before

SceneManager.LoadScene("Level2"); // music stops, score resets

✓ After

DontDestroyOnLoad(gameObject); // music and score persist across scenes

What It Enables

You can create smooth, continuous gameplay experiences where key objects survive scene changes effortlessly.

Real Life Example

In a game, the background music player object uses DontDestroyOnLoad so the music never stops even when the player moves from the main menu to the game level.

Key Takeaways

Scene changes normally destroy all objects, losing data or effects.

DontDestroyOnLoad keeps marked objects alive across scenes.

This makes managing persistent data or effects easy and reliable.