Let’s Play Test: Finding Bugs Before They Find You

Have you ever built a LEGO castle, only to realize the drawbridge doesn’t actually move? Or maybe you wrote a story, but forgot to check if the ending made sense?

In game development, we call this playtesting. It is the fun part where you (or your friends) actually play the game to see if it works.

Today, you will learn how to test your Fortnite island. You will learn how to fix mistakes and make sure your game is ready for everyone to enjoy.

What You'll Learn

• What playtesting really means.
• How to use Live Edit to see changes instantly.
• How to invite friends to help you test.
• Why checking object scale is super important.

How It Works

Think of your island like a science experiment. You build something, then you test it to see if it explodes (in a fun way!) or works perfectly.

What is a Playtest?

A playtest is just playing your game to find bugs. A bug is a mistake in the code or design that breaks the game. Maybe a door won’t open. Maybe a trap misses. Playtesting helps you find these bugs before other people play.

Live Edit: The Magic Bridge

When you are working in UEFN (the editor), you don’t always have to stop and restart the game. You can use Live Edit.

Imagine a magic bridge between your editor and the game. When you change a wall color in UEFN, the bridge lets that change appear in the game immediately. This saves you so much time!

Checking Scale

When you place objects, they might look small in the editor. But when you play, they might look tiny to a player. This is called scale.

Scale is how big or small an object is. If a tree looks big to you but tiny to a player, it is the wrong scale. Playtesting helps you see if things look right.

Let's Build It

We are going to build a simple Jump Pad. We will test it to make sure it launches you high enough. Then, we will use Live Edit to fix it if it is too low.

Step 1: Build the Jump Pad

1. Open UEFN and create a new island.
2. Place a Jump Pad device on the ground.
3. Place a Player Spawn near the jump pad.
4. Place a Target (like a balloon or a prop) high in the air.

Step 2: Test It (Playtest)

1. Click the Play button in UEFN.
2. Your character will spawn. Walk onto the jump pad.
3. Watch closely: Do you reach the target?
   • Yes? Great job! The scale is perfect.
   • No? Don’t worry. This is why we playtest!

Step 3: Fix It with Live Edit

If the jump pad was too weak, we can fix it without restarting.

1. Stop playing and go back to UEFN.
2. Select the Jump Pad.
3. In the settings, increase the Launch Force. Make it stronger.
4. If Live Edit is turned on, the change might happen instantly in the game window.
5. If not, click Push Changes to send the update to the game.
6. Play again. Did you reach the target now?

The Code Behind the Fun

Here is a simple Verse script that could control a jump pad. It checks if a player touches the pad.

# This is a simple script for a Jump Pad
# It makes the pad launch players when they touch it

Jump_Pad = struct:
    # This is a device we place in the world
    # It is like a box that holds our code
    device: Device

    # This function runs when the game starts
    On_Begin_Play := func():
        # We tell the device to listen for touches
        device.On_Interact += func(interaction: Interaction):
            # If a player touches the pad...
            if (interaction.Actor.Is_Player()):
                # ...we launch them into the air!
                # We don't need complex math here.
                # The device handles the physics.
                device.Apply_Launch_Force(1000.0)

What does this do?

• struct: A way to group our code together.
• On_Begin_Play: Runs once when the game starts.
• On_Interact: Runs every time something touches the pad.
• Apply_Launch_Force: The command that makes the jump happen.

Try It Yourself

Now it is your turn!

Challenge: Build a Prop Mover device. Make a platform that moves up and down.

1. Place the Prop Mover.
2. Set it to move up 10 studs.
3. Playtest it.
4. The Problem: When you stand on it, does it move smoothly? Or does it jerk?
5. The Fix: Use Live Edit to change the speed. Try making it slower.

Hint: Look for the "Speed" or "Duration" setting in the Prop Mover properties. Smaller numbers often mean smoother movement.

Recap

• Playtesting is playing your game to find bugs.
• Live Edit lets you see changes in the game without restarting.
• Always check scale to make sure objects look right.
• Testing is not just for experts. It is for every creator!

You are now a playtester! Keep building, keep testing, and have fun.

References

• https://dev.epicgames.com/documentation/en-us/fortnite/unreal-editor-for-fortnite-glossary
• https://dev.epicgames.com/documentation/en-us/fortnite/first-island-04-playtest-your-island-in-fortnite
• https://dev.epicgames.com/documentation/en-us/uefn/unreal-editor-for-fortnite-glossary
• https://dev.epicgames.com/documentation/en-us/fortnite/adding-playtesters-in-fortnite-creative
• https://dev.epicgames.com/documentation/en-us/fortnite/fortnite-glossary