Build settings and scene order in Unity - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Scene Loading Order in Build Settings

Consider a Unity project with three scenes added to the Build Settings in this order: Menu, Level1, and Level2. The first scene is set as the default scene to load on game start.

What scene will be loaded first when the game runs?

A No scene will load automatically

B Level1

C Level2

D Menu

💡 Hint

Check which scene is at index 0 in the Build Settings list.

The first scene in the Build Settings list (index 0) is the one Unity loads automatically when the game starts. Here, Menu is first, so it loads first.

🧠 Conceptual

intermediate

Effect of Scene Order on SceneManager.LoadScene

In Unity, if you call SceneManager.LoadScene(1), which scene will load?

Assume the Build Settings have scenes in this order: Intro (index 0), Game (index 1), Credits (index 2).

A Credits

B Game

C Intro

D An error occurs because index 1 is invalid

💡 Hint

Scene indices correspond to their order in Build Settings starting at 0.

SceneManager.LoadScene(1) loads the scene at index 1 in Build Settings, which is 'Game'.

❓ Predict Output

advanced

What happens if a scene is missing from Build Settings?

Given this code snippet in Unity:

using UnityEngine;
using UnityEngine.SceneManagement;

public class TestScene : MonoBehaviour {
    void Start() {
        SceneManager.LoadScene("MissingScene");
    }
}

Assuming MissingScene is not added to Build Settings, what will happen when this runs in a built game?

A Unity will throw a runtime error and fail to load the scene

B The game will load the scene anyway without errors

C The game will load the first scene in Build Settings instead

D The game will freeze without any error message

💡 Hint

Think about what happens if a scene name is not found in the build.

If a scene is not included in Build Settings, Unity cannot load it by name at runtime and throws a runtime error.

❓ Predict Output

advanced

Scene Count in Build Settings

If your Unity Build Settings list contains these scenes in order: Start, LevelA, LevelB, End, how many scenes does SceneManager.sceneCountInBuildSettings return?

A 3

B Depends on the active scene

C 4

D 5

💡 Hint

Count all scenes listed in Build Settings.

SceneManager.sceneCountInBuildSettings returns the total number of scenes listed in Build Settings, which is 4 here.

🧠 Conceptual

expert

Impact of Scene Order on Build Size and Loading

Which statement about the order of scenes in Unity Build Settings is correct?

A All scenes listed in Build Settings are included in the build regardless of order, but the order determines their index for loading

B The first scene in Build Settings is always included in the build, but other scenes are only included if loaded at runtime

C Scenes not at index 0 are excluded from the build and must be loaded from asset bundles

D The order of scenes in Build Settings affects the compression level of each scene in the build

💡 Hint

Think about what Build Settings controls for scenes in a build.

All scenes added to Build Settings are included in the build. The order only sets their index used for loading scenes by index.

Practice

1. What does the Build Settings window in Unity control?

easy

A. Which scenes are included in the final game build

B. The resolution of the game window

C. The color scheme of the editor

D. The physics settings of the game

Solution

1. Step 1: Understand the purpose of Build Settings

   The Build Settings window lists scenes to include in the game build and their order.

2. Step 2: Identify what Build Settings controls

   It controls which scenes are packaged into the final game, not editor or physics settings.

3. Final Answer:

   Which scenes are included in the final game build -> Option A

4. Quick Check:

   Build Settings = Scenes included [OK]

Hint: Build Settings = scenes included in game build [OK]

Common Mistakes:

• Confusing Build Settings with editor appearance
• Thinking it controls physics or resolution
• Assuming it sets scene start order only

2. Which of the following is the correct way to add a scene to the build in Unity?

easy

A. Drag the scene file into the Build Settings window's Scenes In Build list

B. Right-click the scene in Project and select 'Add to Build'

C. Open the scene and press Ctrl+B

D. Rename the scene file to include 'build' in its name

Solution

1. Step 1: Recall how to add scenes to build

   In Unity, you add scenes by dragging them into the Scenes In Build list in Build Settings.

2. Step 2: Evaluate the options

   Only dragging the scene file into Build Settings is correct; other options are invalid or do nothing.

3. Final Answer:

   Drag the scene file into the Build Settings window's Scenes In Build list -> Option A

4. Quick Check:

   Add scene = drag to Build Settings [OK]

Hint: Add scenes by dragging into Build Settings list [OK]

Common Mistakes:

• Trying to add scenes by renaming files
• Using keyboard shortcuts that don't add scenes
• Expecting context menu to add scenes automatically

3. Given the following scenes in Build Settings in order: ["Menu", "Level1", "Level2"], what will SceneManager.LoadScene(1) load?

medium

A. The scene named "Menu"

B. The scene named "Level1"

C. The scene named "Level2"

D. An error because index 1 is invalid

Solution

1. Step 1: Understand scene indexing in Build Settings

   Scenes are indexed starting at 0 in the order listed in Build Settings.

2. Step 2: Identify scene at index 1

   Index 0 = "Menu", index 1 = "Level1", index 2 = "Level2".

3. Final Answer:

   The scene named "Level1" -> Option B

4. Quick Check:

   Index 1 = second scene = Level1 [OK]

Hint: Scene index starts at 0 in Build Settings [OK]

Common Mistakes:

• Assuming index 1 is the first scene
• Confusing scene names with indexes
• Thinking index 1 causes an error

4. You try to load a scene by index using SceneManager.LoadScene(3), but get an error. What is the most likely cause?

medium

A. SceneManager.LoadScene only accepts strings

B. You must use scene names, not indexes

C. The scene file is missing from the Project folder

D. The scene at index 3 is not added to Build Settings

Solution

1. Step 1: Understand scene indexing and Build Settings

   Scene indexes correspond to the order in Build Settings; index 3 means the fourth scene.

2. Step 2: Identify cause of error

   If index 3 is out of range, it means fewer than 4 scenes are added to Build Settings.

3. Final Answer:

   The scene at index 3 is not added to Build Settings -> Option D

4. Quick Check:

   Index out of range = scene missing in Build Settings [OK]

Hint: Check Build Settings scene count before loading by index [OK]

Common Mistakes:

• Thinking indexes are unrelated to Build Settings
• Believing LoadScene only accepts names
• Assuming missing file causes this specific error

5. You want your game to start with the "Intro" scene, but currently the "MainMenu" scene is first in Build Settings. How can you fix this without renaming scenes?

hard

A. Call SceneManager.LoadScene("Intro") in the first scene's script

B. Change the scene file name to "00_Intro"

C. Drag the "Intro" scene to the top of the Scenes In Build list

D. Remove "MainMenu" from Build Settings

Solution

1. Step 1: Understand scene start order in Build Settings

   The first scene in the Scenes In Build list is the one that starts when the game runs.

2. Step 2: Adjust scene order without renaming

   Drag the "Intro" scene to the top of the list to make it the first scene loaded.

3. Final Answer:

   Drag the "Intro" scene to the top of the Scenes In Build list -> Option C

4. Quick Check:

   First scene in Build Settings = start scene [OK]

Hint: First scene in Build Settings list starts game [OK]

Common Mistakes:

• Renaming files instead of reordering scenes
• Removing scenes unnecessarily
• Relying only on script calls without build order