A daily whodunit puzzle, in ChatGPT
Alibi Hour is a short logic mystery that everyone gets on the same day: something has gone missing, four suspects each account for six ten-minute slots, and exactly one of them, the culprit, lies in every answer. You ask questions in ChatGPT (up to 10), catch the story that can't be true, and accuse; a solver has checked that only one answer is possible and tells you the fewest questions that prove it.
Updated · The Open Apps, Inc.
How to play
- Open the case. In ChatGPT, say “Let's play today's Alibi Hour case”. A new case opens for everyone at 00:00 UTC.
- Read the case file. It tells you what went missing, from which room, and the exact ten minutes it happened (a door sensor, an alarm, a stopped clock).
- Ask about a time. “Ask Ben where he was at 8:30.” Each answer is one sentence, the same for everyone who asks it. The card keeps a timeline.
- Look for the story that can't fit. Three suspects always tell the truth. Two answers that clash mean one of those two is the liar; a walk across the house in ten minutes means somebody's alibi is impossible.
- Accuse. Name the culprit. You'll see whether your own answers proved it, par for the case, and how you did against everyone who played today.
What makes a case fair
Every case is written by a generator and then read by a solver before anyone sees it. The solver tries every possible culprit against every statement and the map, keeps only cases where exactly one suspect fits, and works out par: the smallest set of questions that rules everyone else out.
So there is always a clean answer, you never need outside knowledge, and a good solve is measurable: “proven in 4 questions, par 4” means you found the shortest path.
Ways to get a daily mystery
Different formats suit different moods. Here's how they differ.
| Alibi Hour | Asking a chatbot to make up a mystery | A logic-puzzle book | |
|---|---|---|---|
| Same case for everyone | Yes, one a day | No | Yes, if you have the same book |
| Guaranteed single answer | Yes: checked by a solver | No: the story can change as you ask | Yes, if well edited |
| Who knows the answer | Only the server, until you accuse | The chatbot that wrote it | The answer pages at the back |
| Score | Questions used against par, and a daily percentile | None | None, or time |
| Play with friends in a room | Yes: party mode with private phone sheets | Hard: one screen sees everything | Pass the book around |
Compared by format, 14 October 2026.
Use it in ChatGPT
Alibi Hour is a ChatGPT plugin. Type one of these:
- “Let's play today's Alibi Hour case”
- “Ask Ben where he was at 8:30”
- “I think it was Cleo”
Questions
- Is Alibi Hour a murder mystery?
- No. Every case is non-violent: a trophy, a cake or a robot's chip goes missing, and nobody gets hurt.
- How long does a case take?
- Five to ten minutes for most people. Easy cases run early in the week; Friday to Sunday are hard.
- Can ChatGPT just tell me the answer?
- No. ChatGPT doesn't know it: statements reach it only when you ask a question, and the culprit only after you accuse.
- What happens if I run out of questions?
- After 10 questions you have to accuse. A right guess that your answers didn't prove counts as lucky, not proven.
- Do I need an account?
- No. Alibi Hour knows you only by an anonymous ID that ChatGPT provides, and it shows no ads.