Alibi

Work through a grid of suspects and the facts attached to each, their Room, their Weapon and their Motive. Clues tell you which combinations are possible and which are ruled out. Use pure elimination to pin every detail to the right suspect and expose the one whose story makes them the culprit.

• Read each clue and mark which suspect-fact pairings it confirms or eliminates.
• Cross-reference Room, Weapon and Motive until only one consistent solution remains.
• Name the killer once the deductions leave no other possibility.

• Daily, one shared mystery for every player each day.
• Practice, endless fresh cases to keep deducing.

• Desktop: click cells to mark, confirm or rule out connections.
• Phone & tablet: tap to mark the grid, fully touch playable.

• Mark negatives aggressively, ruling out wrong pairings narrows the grid faster than chasing positives.
• When two facts can only belong to two suspects, lock the rest of that row and column.
• Re-read clues after each deduction; one new fact often unlocks a chain of others.

This is the logic-grid puzzle, the form whose best-known specimen is the zebra puzzle — a set of categories, a list of constraints, and a solution reachable by elimination alone.

The original dressing is the murder mystery: suspects with a Room, a Weapon and a Motive, which is the vocabulary Cluedo gave the genre.

The framing does real work. A bare grid of attributes gives you nothing to hold on to, while a room and a weapon are memorable, so the same elimination chain becomes easier to carry in your head — which is why the format has outlived every particular puzzle written in it.

Alibi is an original free browser game in the logic-grid deduction genre, framing a daily elimination puzzle as a murder mystery you crack through reasoning alone.

A free, original browser game on PlayPendium. No download, no install.