How to fix lag issues in rock paper scissors game
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GameOptimizer_Dev
Posted on July 27, 2025 • Beginner
🎮 Rock Paper Scissors game is lagging badly
Hey everyone! I’ve been working on a rock paper scissors game but it’s running really slowly and sometimes freezes up. The game works but it’s super laggy and not fun to play.
I think the problem might be with how I’m checking for player moves and updating the display, but I’m not sure how to fix it. Any help would be amazing!
Project link: My Rock Paper Scissors Game
Thanks in advance! 🙏
PerformanceOptimizer
Replied 15 minutes later • ⭐ Best Answer
Great question @GameOptimizer_Dev! Lag in Scratch games is usually caused by inefficient loops and too many checks happening every frame. Here’s how to fix your rock paper scissors game:
🔍 Common Lag Causes in Rock Paper Scissors
Here’s what typically causes performance issues:
🚀 Step 1: Replace Forever Loops with Events
❌ Laggy Code (Don’t do this):
when flag clicked forever if <key [r v] pressed?> then set [player choice v] to [rock] wait [2] seconds end if <key [p v] pressed?> then set [player choice v] to [paper] wait [2] seconds end if <key [s v] pressed?> then set [player choice v] to [scissors] wait [2] seconds end end
✅ Optimized Code (Much better!):
when [r v] key pressed set [player choice v] to [rock] broadcast [player chose v] when [p v] key pressed set [player choice v] to [paper] broadcast [player chose v] when [s v] key pressed set [player choice v] to [scissors] broadcast [player chose v]
🎯 Step 2: Use Broadcast Messages for Game Flow
Instead of constantly checking variables, use broadcasts to control game flow:
when I receive [player chose v] // Generate computer choice set [computer choice v] to (item (pick random [1] to [3]) of [rock paper scissors v]) // Show choices broadcast [show choices v] wait [1] seconds // Determine winner broadcast [check winner v] wait [2] seconds // Reset for next round broadcast [new round v]
🎨 Step 3: Optimize Visual Updates
For showing/hiding costumes efficiently:
when I receive [show choices v] // Player sprite if <(player choice) = [rock]> then switch costume to [rock v] else if <(player choice) = [paper]> then switch costume to [paper v] else switch costume to [scissors v] end end show // Computer sprite if <(computer choice) = [rock]> then switch costume to [rock v] else if <(computer choice) = [paper]> then switch costume to [paper v] else switch costume to [scissors v] end end show
🏆 Step 4: Efficient Winner Detection
Clean logic for determining the winner:
when I receive [check winner v] if <(player choice) = (computer choice)> then set [result v] to [It's a tie!] else if <<(player choice) = [rock]> and <(computer choice) = [scissors]>> then set [result v] to [You win!] else if <<(player choice) = [paper]> and <(computer choice) = [rock]>> then set [result v] to [You win!] else if <<(player choice) = [scissors]> and <(computer choice) = [paper]>> then set [result v] to [You win!] else set [result v] to [Computer wins!] end end end end // Show result say (result) for [2] seconds
🔄 Step 5: Clean Reset System
Proper cleanup between rounds:
when I receive [new round v] // Hide choice sprites hide // Clear variables set [player choice v] to [] set [computer choice v] to [] set [result v] to [] // Show instructions say [Press R for Rock, P for Paper, S for Scissors] for [3] seconds
⚡ Step 6: Additional Performance Tips
Here are some extra optimizations:
Avoid Unnecessary Waits:
// ❌ Don't do this forever wait [0.1] seconds // check something end // ✅ Do this instead when I receive [something happened v] // respond immediately
Use Custom Blocks for Repeated Code:
define show choice (choice) if <(choice) = [rock]> then switch costume to [rock v] else if <(choice) = [paper]> then switch costume to [paper v] else switch costume to [scissors v] end end show
Limit Visual Effects:
// Keep effects simple for better performance when I receive [player wins v] repeat [3] change [color v] effect by [25] wait [0.1] seconds end clear graphic effects
These changes should make your game run much smoother! The key is to avoid continuous checking and use event-driven programming instead. Good luck! 🎮✨
GameOptimizer_Dev
Replied 30 minutes later
@PerformanceOptimizer This is incredible! Thank you so much! 🎉
I replaced all my forever loops with broadcast messages and the game is running perfectly now. The difference is night and day! I had no idea that forever loops could cause so much lag.
One quick question - should I avoid using forever loops completely, or are there times when they’re okay to use?
PerformanceOptimizer
Replied 1 hour later
@GameOptimizer_Dev Great question! Forever loops aren’t always bad - they’re perfect for:
- 🎵 Background music loops
- 🌟 Continuous animations (like rotating stars)
- 🎮 Game physics (like gravity)
- ⏰ Timers and countdowns
The key is to always include a wait block in forever loops to prevent lag. Even wait 0.01 seconds makes a huge difference!
Vibelf_Community
Pinned Message • Moderator
🚀 Want to Master Game Optimization?
Excellent discussion on performance optimization! For those looking to create even faster and more efficient games, our community can help you with:
- ⚡ Advanced performance techniques
- 🎮 Complex game architecture
- 🔧 Debugging and profiling
- 📊 Memory management in Scratch
📚 Related Topics
- How to debug slow Scratch projects?
- Best practices for efficient coding
- Creating smooth animations without lag
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