The 3% Rule

100 hidden-rule puzzles and a Daily Challenge. 29 elements obey the rule, one doesn't. Can you spot it before the clock runs out?

Every grid hides a rule. Everything obeys it. Except one.

The 3% Rule is a puzzle game of pure observation, born from the book of the same name. Each level shows you a grid of 30 numbers, letters, dominoes, clocks, cards or symbols. They all follow one hidden rule, all but one. Your job: spot the element that doesn't belong.

The title is your first clue.

HOW TO PLAY • Look at the grid and read the level title. • Tap the element that breaks the rule. • Three wrong taps and the level is lost. Try again: the layout changes, the rule stays. • Stuck? Use a Hint, or reveal the Solution. Clear levels to refill your reserve, or top it up in the shop.

FEATURES • 100 levels that start obvious and end devious: palindromes, prime numbers, Roman numerals, binary, clocks, playing cards, dominoes and more. • Speed levels against the clock, plus Hard and Extreme levels for the sharpest eyes. • Daily Challenge: the same 10 grids for everyone each day. Post your time under a nickname and climb the leaderboard. • A new layout every time you play, so you can't just remember the spot. • Earn up to three stars per level and beat your best time. • Original soundtrack and sound effects, which you can switch off. • Play in English, French, Spanish, German, Italian, Portuguese, Japanese or Chinese. • All 100 levels work offline, without an account.

FREE TO PLAY • A short ad plays every 10 levels and after the Daily Challenge. One purchase removes them for good. • The shop also sells packs of hints and solutions, and tips if you want to support the game. • A free account, opened with a code sent by e-mail, is only needed for the Daily Challenge leaderboard and for hint and solution packs, so they follow you to a new phone.

From the book The 3% Rule. More puzzles at the3percentrule.com.