Odd One Out is a free odd one out game online: a visual logic puzzle where every round shows four to nine figures and all but one of them share a hidden rule. Each figure has a shape, a colour, a fill and a number of copies, and the rule can be as plain as "all the others are red" or as sly as "every triangle is yellow, every square is blue" or "each one has twelve corners in total". Tap the figure that does not belong and the game tells you the rule in one sentence. Ten levels of ten rounds climb from a single obvious difference to crowded boards full of decoys, and a Streak mode runs until your first wrong tap. Every round is checked before it is shown, so exactly one figure is the odd one out under the simplest rule that fits. Works with a mouse, a touch screen or the number keys; no download, no account.
How to play Odd One Out
- Each round shows four to nine figures on tiles. A figure is one to six copies of a shape — circle, triangle, square, pentagon or hexagon — in yellow, red or blue, filled solid, dotted or hollow.
- All the figures but one follow a rule. Find the one that does not and tap it (or press its number key, 1 to 9).
- The rule can be about one thing — every other figure is red, or has three shapes — or about how two things go together, like "every triangle is yellow and every square is blue". On the later levels it can be about counting: as many shapes as each shape has sides, or the same number of corners in total.
- A right answer lights the figure green and shows the rule in one sentence. Press Next (or Enter) for the next round.
- A wrong tap crosses the figure out and adds five seconds to your time; keep looking. The clock only runs while a round is waiting for an answer, so reading the explanation is free.
- Levels have ten rounds. Your score is your thinking time plus the penalties, and stars are set per level: finish a level to unlock the next one.
- Streak mode deals rounds that get harder every four, from level 1 up to level 10. One wrong tap ends the run.
Tips
- Start with what is almost uniform. If every figure but one is hollow, that one is your answer; an attribute where two figures differ from the rest is a decoy, not a rule.
- Being the only one of something counts: if exactly one figure is a hexagon, the others all share "not a hexagon". The game never shows two figures that are each the only one of something, so if you find one, you have found the answer.
- When no single attribute works, pair them up. Group the figures by shape and see whether each group keeps to one colour, fill or number; the figure that spoils a group is the odd one.
- On the counting levels, count sides, not just shapes. Three triangles and four squares both "match their sides"; four triangles and three squares both have twelve corners.
- Colour is never the only clue you need to see: the yellow, red and blue sit far apart in lightness, so they stay three different greys.
- A wrong guess costs five seconds; on the early levels a careful look usually takes less than that.
FAQ
Is Odd One Out free to play?
Yes. Odd One Out is free to play online with no download, no account and no in-game purchases. All ten levels and Streak mode are in the browser.
Can a round have two right answers?
No. Before a round is shown, the game checks every rule of the kinds it uses — one attribute shared, one value unique, one attribute deciding another, all different, sides and corners — against every figure. It only keeps rounds where exactly one figure is the odd one out under the simplest rule that fits, and no other figure is the odd one out under any rule as simple as the intended one.
What kinds of rules are there?
Levels 1 to 5 use one attribute: all the others share a shape, colour, fill or number of shapes. Level 6 brings in pairs, where one attribute decides another — every circle is dotted, every square is solid. Levels 9 and 10 add counting: as many shapes as each shape has sides, or the same number of corners in total.
How are the stars decided?
Your level score is the thinking time for all ten rounds plus five seconds for each wrong tap. Each level has its own star times, set by testing model players of different speeds on sets they were not tuned on. Three stars on level 1 need under two seconds a round; on level 10 about twenty-one.
What is Streak mode?
An endless run. It starts with level 1 rounds, moves up a level every four right answers and stays at level 10 once it gets there. The first wrong tap ends the run and shows you the answer and the rule you missed. Your best streak is saved.
Is this a spot the difference game?
No. In spot the difference you compare two pictures for changed details. Here nothing is hidden or tiny: every figure is in plain view, and the puzzle is working out which rule the others share.
Is it colour-blind friendly?
The three colours were chosen to differ in lightness as well as hue, so they read as light, middle and dark grey without colour vision, and every shape has a dark outline. Fill and shape never depend on colour.
Does Odd One Out work on mobile?
Yes. The tiles are laid out in whichever grid makes them biggest on your screen, and each tile is a large tap target. It works upright or sideways.