Motive: a murder mystery you solve with logic

Motive borrows the rule that makes sudoku work, one per row and one per column, and turns it into a crime scene. Instead of digits you place suspects on a floor plan. No two people share a row or a column, and neither shares one with the body.

The statements under the board tell you the rest: who stood beside whom, who was in which room, who was alone. Together they fix exactly one place for everyone, and the person left alone in the body's room is your killer.

• Each suspect stood on exactly one square; your job is to work out which.
• No two people share a row or a column, and the body takes up its own row and column too.
• Tables, plants, bookcases and pianos block their squares. Rugs, chairs and sofas can be stood on.
• Every statement is true.
• Exactly one suspect ends up in the room with the body, alone with it. That suspect is the killer.

Cases mix 22 kinds of statement across five difficulty tiers. A suspect might be beside someone (directly above, below, left or right, and inside the same room), somewhere in a room, in a given row or column, standing on a piece of furniture, alone in a room, against an outer wall, or north, south, east or west of someone else. Some statements pair two suspects, and a few describe the killer without naming them.

The first 93 cases are paced step by step: floor plans grow from 5×5 to 8×8 and the cast from four suspects to seven. After that new cases keep coming, generated on your phone, and every one is checked to have a single answer you can reach without guessing.

A placement that breaks a statement costs a heart; lose three and the trail goes cold, so the case starts again. Rule out lets you pencil a cross on any square you have eliminated, and undo takes back a move. When you are stuck, a hint shows where someone can still be; free hints refill over time, and a short ad unlocks more.

Motive is fully translated into 40 languages, statements included, so every clue reads naturally wherever you play.