Rularoo
Easy
Three terms, 1 to 30. A gentle vocabulary and par of two to five probes.
Play →Guess the rule, not the answer.
You are shown three numbers. They follow a rule. Find it.
Rularoo is a daily deduction game built on Peter Wason's 2-4-6 task, the experiment that showed people look for evidence that confirms them and almost never for evidence that would prove them wrong.
Today the game opens with something like
- 2
- 4
- 6
Most people guess "add two each time". Most people are wrong, and every test they run says FITS.
Why it is harder than it looks
The rule people reach for is almost always narrower than the real one. A narrower rule only accepts sequences the real rule also accepts, so every sequence you test to confirm your idea comes back FITS. Confirmation cannot get you out. The probe that frees you is one you expected to fail.
Three puzzles a day
Rularoo is better in the app
Every puzzle here is free to play in the browser, today's and the whole archive. The app is for the part a browser cannot do: a puzzle waiting for you every morning, a streak that survives a missed one, and the Coach telling you which probe cost you the round.