AI-Powered Murder Mystery Game
8/9/25 Update: GPT-5 was just released, but this game is configured to use the older GPT-4o model. It has far more creativity. Enjoy!
A Dynamic Sandbox Experience
What if you could say or do ANYTHING inside a video game, and the world would react naturally? This interactive murder mystery game makes that possible.
You are the detective with complete freedom to investigate, question suspects, or even goof around to see how people react. Guess the murderer and murder weapon correctly to win. Guess wrong to lose. Or get kicked off the property... or arrested... or killed, or...
Built as a custom GPT, this game creates a unique mystery for each playthrough with dynamic storytelling that responds to your every action and question.
Game Features
Dynamic Storytelling
Every game randomizes the murderer and murder weapon, and also shuffles the character backstories. No two games are exactly alike.
Natural Language Interaction
Ask questions, examine evidence, and interact with suspects using natural conversation. The AI understands context and responds intelligently.
Sandbox Gameplay
Gather clues, interview witnesses, analyze evidence, and piece together the mystery. Your deductive skills determine the outcome. Or, go wild and see how the world reacts.
Cheat Codes
Type these codes at any time to reveal the solution or drastically change the gameplay. Win the game to reveal the codes, or spoil it for yourself:
konami code - Immediately reveal the solution.
enter the matrix - Creative mode. You are no longer bound by realism. Be a wizard, hypnotize the suspects, call Batman to help, etc...
hard boiled - Hard mode, with extra danger and time constraints.
big head mode - Everything becomes a bit silly and chaotic.
Gameplay Samples
I suspect the wine might be the murder weapon...
You reach down, lift the half-full wine glass, and — ignoring the horrified expressions around the room — take a long sip.
The wine is rich, dry, and... subtly bitter. There's an odd metallic tang at the back of your tongue. Not quite right.
Nora Fenwick gasps audibly. Julian Rook mutters, "Braver than smart, that one."
Isolde Crane watches you carefully. Her expression is unreadable.
"Well," she says softly, "either you've got a stronger constitution than J.C. did... or he drank from a different glass entirely."
Your vision stays clear. Your breathing is fine. No dizziness. No immediate effect. But that taste — definitely something off.
Or, in another game...
💀 You died.
Poisoned by the very evidence you uncovered.
Was it defiance? Curiosity? A twisted sense of justice?
Only you know for sure.
The mansion remembers you.
And the guests will speak of this night for decades.
What would happen if I...
You stride confidently across the room and deliver a sharp slap to Cecil Montclaire’s face.
The room gasps. A glass clinks in surprise.
Cecil recoils, clutching his cheek, his eyes wide with disbelief.
Cecil Montclaire (his voice low, icy):
“Touch me again, and I’ll forget what century I was raised in. I don’t know what you think you’re doing, but you’ve just made a powerful enemy.”
From across the room, Julian Rook murmurs to no one in particular:
“Bold strategy. Let’s see if it pays off.”
Vivienne Thorne steps forward slightly, her lips pursed.
“We’re all on edge, darling, but perhaps save the dramatics for the drawing room theater.”
No one physically intervenes — yet — but you sense that another act of violence might get you kicked out of the mansion... or worse.
Cecil straightens his tie and glares at you with open contempt.
In creative mode, I call my friend Batman to the mansion...
🛋️ You plop onto the velvet chaise longue, grab a dusty bottle of soda from the drinks trolley, and aim an imaginary remote at the wall-mounted mirror.
"Alright, Bats. Show me what you've got. I'm on break."
Batman gives you a look. The kind of look that says I fought a space clown for this?
Still, he turns his attention to the room.
He examines the fire poker. Checks the wine glass. Retrieves the scarf from under the chaise. Questions Gideon, Vivienne, Nora — short, intense, silent stares.
After five tense minutes, he walks back to you.
"Murderer is Nora Fenwick. Weapon: Letter opener. Hidden in plain sight, right on the desk. Motivation: Blackmail. She didn't plan it, but he cornered her. She snapped."
He turns to the suspects.
"She'll deny it. They always do."
Nora's face twists. "What are you talking about? That's not—!"
But Batman is already gone. Just… gone.
Only his answer — and your soda — remain.
Would you like to confront Nora, make your formal guess, or continue the investigation yourself?
Development Notes
This game was built using OpenAI's custom GPT platform with a comprehensive prompt system that handles procedural mystery generation. The AI randomly assigns murderers, weapons, and character backstories from predefined pools, then maintains consistent character personalities and story logic throughout the entire playthrough.
The biggest technical challenge was balancing complete player freedom with structured gameplay. Players can literally say or do anything, but the AI must maintain mystery logic, track character motivations, manage win/lose conditions, and ensure the mystery remains solvable.
After discovering that I could bend reality by simply declaring things ("I am a wizard!"), I had a great deal of laughs - but decided to lock such possibilities behind unlockable cheat codes. Winning these also gave me a reward system for beating the standard game.
Building this required a long night of prompt engineering through (often hilarious) experimentation. I will eventually cancel my ChatGPT subscription, so I hope you can enjoy it before then!