Thirty-One Card Game (2025)

I have created a multiplayer card game without writing a single line of code.

In 10 days I ran an experiment: to develop a complete application using only AI (Claude Code, Gemini, and ChatGPT), following what is called "vibe coding".
The challenge: to program zero lines myself.

The result? A functional online version of Thirty-One, a card game I used to play in college.

What I've learned

✅ It's possible to program without knowing how

The barrier to entry has been dramatically reduced. Although knowing how to program and having a prepared environment helps a lot.

⚠️ Hallucinations are real

If you don't specify very clearly what you want, the AI makes things up. In my case: poker mechanics that didn't exist in the game, visual template systems I hadn't asked for...

🎯 Small changes work better

Small iterations = fewer errors.

💰 Tokens run out fast

I had to switch between Claude Code, Gemini-cli, and ChatGPT. If you know how to program and make small adjustments, you save a lot of tokens.

🔄 Git is essential

When the AI does strange things, you can go back. Friends who have tried the game have sent me some pretty curious screenshots.

🧪 Automatic tests are key

Asking the AI to generate tests and run them with every change avoids many problems (although you have to check that the tests are correct).

📱 Responsive is complicated

Making it work well on both mobile and desktop consumed a lot of tokens. The card animations, on the other hand, came out perfect the first time.

🐛 Errors in production

I integrated Sentry.io to capture errors that appeared on real users' devices and that I didn't see on my computer.

🚀 Automatic deployment helps

I have a server with Dokploy linked to GitHub that deploys automatically, Vercel/Netlify style.

The most important conclusion

Now that the game is public and functional, I find it risky to continue developing only with AI. When you upload changes, shortly after someone sends you a screenshot with something strange and you don't know how it happened. To add new features, I think I should do it myself to maintain control.

The game

Thirty-One is simple but addictive: each player has 3 cards and adds up the ones of the same suit to reach 31. You can change one card, all of them, or pass. When someone thinks they have a good score, they can "close" and give the others one last round.

Try it yourself: https://trentau.albertsarle.com

Publication date: September 2025 More details about the process and learnings at LinkedIn

Tech Stack

• HTML5 & CSS3
• Vanilla JavaScript
• Responsive Design
• Touch Controls
• Internationalization (i18n)

Features

• Multi-language support (EN, ES, CA)
• Mobile-optimized interface
• Traditional Thirty-One rules
• AI opponents with smart gameplay trentau.albertsarle.com