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Locked-Room Mystery

Locked-Room Mystery is an AI-native detective game where Google Gemini serves as the Game Master (GM), generating and running unique cases in real time.

Code Video Cerebral Valley

Core trick

Generates a JSON case file, then runs a second Gemini call that rewrites game-master answers contradicting the hidden case data.

Tags

agents

Description

Locked-Room Mystery is an AI-native detective game where Google Gemini serves as the Game Master (GM), generating and running unique cases in real time. Core Features Dynamic Generation: Gemini creates a fresh JSON case file (suspects, killer, trick, motive, evidence) and a matching anime-style background image for every playthrough. AI Game Master: Answers the player's freeform questions dynamically. Designated lying NPCs maintain coherent false testimony throughout the interrogation. Contradiction Guard: A secondary AI call cross-checks GM responses against the hidden case data, rewriting inconsistencies to ensure a fair, solvable mystery. Scoring & Feedback: Evaluates final accusations (S/A/B/C rank), highlights logical weaknesses, reveals the truth, and generates a dynamic result screen image reflecting the score's mood. Conversation Summarizer: Distills the Q&A history into a structured deduction sheet to assist the player's reasoning at any time.
kota-kawa/Gemini3-Hackathon-Mystery-Game★ 00 forksPythonCreated Feb 21, 2026 · last push Feb 23, 2026

README excerpt

> 一番下に日本語版もあります

# 🔍 Locked-Room Mystery

![Python](https://img.shields.io/badge/Python-3776AB?logo=python&logoColor=white)
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> **An AI-powered detective game where Gemini acts as your Game Master**

## 🖥️ UI Preview

<p align="center">
  <img src="assets/images/Gemini3-Hackathon-Mystery-Game-ScreenShot.png" alt="UI Preview" width="1100">
</p>

## 🎬 Demo Video

Click the thumbnail to open the video on YouTube.

| [![Demo Video](https://img.youtube.com/vi/OwgDX0RYm6Y/hqdefault.jpg)](https://youtu.be/OwgDX0RYm6Y) |
| --- |
| Demo Video |

## 🎮 What is this?

This is an **interactive mystery-solving game** where an AI (Google Gemini) plays the role of Game Master (GM). Each playthrough generates a unique locked-room murder case with any setting. Question witnesses, gather evidence, and deduce the culprit before your questions run out!

### ✨ Key Features

| Feature | Description |
|---------|-------------

Team