A weekly thread where we solve a puzzle together chosen from your submissions and creations.

Every Monday, I’ll pick one puzzle, made by or suggested by a community member for everyone to tackle together for the week. Share your theories, progress, and solutions (using SPOILER TAGS where appropriate)

Start submitting your puzzles by sending a mod message Titled: Community Puzzle Submission

This week’s submission is a puzzle created by u/Key-Improvement4850 from Six Figure Logic

Six Figure Logic Website

The first to solve can get a custom ‘Community Puzzle Winner’ user flair.

Happy solving, Solvers!

An interactive crime novel where you read the chapters to gather clues and decode symbols. Make choices on who to interview next. Pick your main suspect to solve the case or make a wrong choice that leads to failure.

Released on 9th July 2026, this is the second instalment of the ‘Can you solve the murder?’ Interactive crime series by Antony Johnston.
Where to buy: Antony Johnston Books

Description from the website:

“In this gripping interactive crime novel, YOU are the detective. At the end of every chapter, YOU decide what to do next…

A village of secrets.
You arrive at the heart of a remote forest to investigate the murder of a young woman, found dead inside an ancient stone circle. She’s a rock singer, who was filming a music video. Now her bandmates are suspects, along with the eccentric locals.

No one is telling the truth.
There’s just one problem: they all have water-tight alibis, and many villagers believe the singer was actually killed by the ‘Stone Warden’ – a figure from local folklore who haunts the forest.
Only YOU can solve the mystery.

Only YOU can solve the mystery
Decide who to interview, decode the strange symbols written on the stone circle, and uncover what the villagers are hiding behind closed doors. Will your choices catch the killer – or will they be your downfall?”

Posting this with the mod team's go-ahead — I messaged first under rule 5.

I build a free daily deduction puzzle called **Deduce**. One case a day: a victim, a set of suspects, a set of rooms and a set of weapons, plus a list of clues you eliminate on a grid until one combination survives. Name who, where, and with what.

**The bit I think matters for this sub:** every case is machine-verified before it publishes. A constraint solver checks two things — that exactly one solution exists, and that it's reachable by pure deduction. If the answer can only be found by trial and error, the case is thrown away and regenerated. You should never have to guess, and if you ever do, that's a bug rather than a design choice.

Five tiers. The first four are 4×4×4 grids with 6–13 clues. The top tier, **Grand Sleuth**, is 5×5×5 plus a fifth axis — each suspect's arrival time — which is the full six-block staircase grid, with 17–18 clues. Some of those clues are deliberate lies you have to catch by contradiction.

How people are actually doing, of those who commit to an accusation:

| Tier | Solve rate |

| Junior | 79% |

| Inspector | 74% |

| Master Detective | 74% |

| Grand Sleuth | 61% |

Just over 1,750 cases solved so far across 204 registered detectives and a lot more anonymous ones. Four different settings, so the cast changes.

Free, no account needed to play, no ads, nothing to buy, runs in the browser. An account only exists to track your streak and unlock the higher tiers.

- Today's case: https://deduce.studio/daily

- Archive of closed cases (no solutions): https://deduce.studio/archive

Full disclosure: I built it solo, in my evenings. Happy to answer anything about how the generator or the verifier works — and genuinely happy to hear where it's too easy, too hard, or unclear.