One day, this thought suddenly crossed my mind.

“Wouldn’t it be fun to play Mafia with AIs?”

A game where you read the room and outplay AI players who all have different MBTI types, blood types, and speaking styles. That game I used to play with relatives and friends as a kid. I tried making it so you can play it solo, too.

And the result… I won solo in Round 1. 🃏
I joined under the name “Clown” to stir things up…
and then I was shocked when my actual role really was Clown 😀

🎮 Let me explain what kind of game this is.

It’s a Mafia game played with AI players powered by Claude AI.
Each AI is set up with a different MBTI type, blood type, personality, and speaking style, and they talk while reading the room like real people.

The game flow goes like this:
☀️ Day discussion (5 min) → 🗳️ Vote (45 sec) → 🌙 Night (40 sec) → 🔁 Repeat

🃏 Roles

Role	Team	Ability
🔪 Mafia	Mafia	Eliminate 1 citizen each night
🚔 Police	Citizens	Investigate 1 player each night (check if they’re Mafia)
💉 Doctor	Citizens	Protect 1 player each night (block Mafia attack)
😊 Citizen	Citizens	No special ability. Find the Mafia through daytime discussion
🃏 Clown	Neutral	If you’re voted out in Round 1, you win solo!

Clown tip: The Clown is neither a citizen nor Mafia. Your only goal is to get voted out in the Round 1 vote. The more suspicious you act, the better 🙂

😂 Actual play log — The Clown Strategy

In this game, I got the Clown role lol

The Clown has one goal: get voted out in the Round 1 vote.

The strategy was simple: from start to finish, keep repeating “I’m the Clown.”

I pretended I was doomed, but I ended up getting voted out—and since I got voted out, that meant I won.
“Ah… I’m screwed” was just acting,
but I didn’t expect the AIs to actually fall for it, so it was hilarious and so satisfying 😀

You can also export and save your chat history, so try sharing those fun moments with your friends.

🤖 AI player traits

The coolest part of this game was how the AIs react like it’s a real conversation.

✔️ If you call their name, they almost always respond (85% chance)
✔️ They reflect what was said during the day in their night actions (e.g., “Doctor, protect the Police” → they may actually protect the Police depending on their judgment)
✔️ Their speaking style and decision-making differ by MBTI and blood type
✔️ If the Clown acts suspicious, they genuinely suspect them

In this game, Hoya (ENFP) kept reacting emotionally, and Luna (INFJ) stayed quiet and then suddenly threw out sharp comments. Blue (ISTJ) calmly fact-checked. It really felt like the characters were alive.

🎮 Want to try it yourself?

👉 Play now : https://mafia-game-lilac.vercel.app

Right now it’s single-player only (vs AI). Multiplayer support is planned later!

To start the game, you’ll need a Claude AI API key. After you enter the game, click the “Issue API” button and you can get one quickly. (You may need to log in.)

API usage costs include a free tier by default, and after that a small fee may apply. I’m not affiliated with this payment and I don’t earn any revenue from it.

🔮 What I want to build next

For now it’s a solo game with AIs, but what I really want is multiplayer.

Having friends join and play mixed in among the AI players. Wouldn’t it be way more fun if a real mind game unfolded where you don’t know who’s AI? I’m planning to try it with my family soon.

When multiplayer is implemented, I’ll come back with another post 🃏

If you have any questions about the AI Mafia game, leave a comment!
Rules, role balance, Clown strategy tips(?)—anything lol

Slowly, steadily — Shinbi Days