Part 8 (C++): Create Game Mode

← Previous: Part 7 (C++) - Create UI | Back to Index | Next: Part 9 (C++) - Polish & Debug Features →

Overview

Create a custom Game Mode to set the default pawn class and manage game rules.

Time: ~5 minutes

Step 8.1: Create STGGameMode C++ Class

Tools → New C++ Class
Choose "Game Mode Base" as parent
Name: STGGameMode
Create Class

Step 8.2: Define Game Mode

STGGameMode.h:

⚠️ IMPORTANT: Replace YOURPROJECTNAME_API with your actual project's API macro (e.g., BULLETHELLCPP_API).

#pragma once

#include "CoreMinimal.h"
#include "GameFramework/GameModeBase.h"
#include "STGGameMode.generated.h"

UCLASS()
class YOURPROJECTNAME_API ASTGGameMode : public AGameModeBase
{
    GENERATED_BODY()
    
public:
    ASTGGameMode();
};

STGGameMode.cpp:

#include "STGGameMode.h"
#include "STGPawn.h"

ASTGGameMode::ASTGGameMode()
{
    // Default to C++ pawn class
    // We'll override this in a Blueprint child to use BP_Player
    DefaultPawnClass = ASTGPawn::StaticClass();
    
    bStartPlayersAsSpectators = false;
}

Note: We use the C++ STGPawn as default. In the next step, we'll create a Blueprint child of this GameMode to set BP_Player as the default pawn. This approach is more flexible than hardcoding Blueprint paths, which can break if files are moved.

Step 8.3: Create BP_STGGameMode Blueprint

We create a Blueprint child of STGGameMode to configure BP_Player as the default pawn:

Content Browser → Right-click in empty space
Select Blueprint Class
In the popup, expand All Classes and search for STGGameMode
Select STGGameMode as parent → Click Select
Name: BP_STGGameMode
Double-click to open the Blueprint
In Class Defaults panel (right side):
- Find Default Pawn Class
- Click dropdown → Select BP_Player
Compile (top toolbar) → Save

Why use a Blueprint GameMode?

Avoids hardcoded paths that break when files move

Allows designers to change settings without recompiling

Standard Unreal Engine practice for configuration

Step 8.4: Set Game Mode in Project Settings

Edit → Project Settings
Project → Maps & Modes
Under "Default Modes":
- Default GameMode → Select BP_STGGameMode (the Blueprint, not the C++ class)
Close Project Settings

⚠️ Important: Make sure to select BP_STGGameMode, not STGGameMode. The Blueprint version has BP_Player configured as the default pawn.

Step 8.4: Test

Create a new level or use existing one:

File → New Level → Empty Level
Save as BulletHellLevel
Add:
- Player Start (from Place Actors panel)
- STGEnemySpawner
- STGGameDirector
- STGHUDManager
- Directional Light (for visibility)
Press Play

Expected Result:

✅ Player automatically spawns at Player Start location
✅ No need to manually drag BP_Player into level
✅ All game systems work together