3-5-7: Last Line Loses

Whoever takes the last line loses.

3-5-7 is a deceptively simple strategy duel built on a century-old mathematical game. Cross out as many lines as you like from a single row — but leave the final line for your opponent, or it's game over.

Easy to learn in one round. Impossible to master without thinking three moves ahead.

AN ENDLESS JOURNEY Battle through The Classic, The Pyramid, The Diamond, The Hourglass and beyond — then keep going forever with endlessly generated worlds. Every level is verified winnable: when you lose, it's because the perfect move was there and you missed it.

TWISTS THAT CHANGE THE MATH Stone barriers split the board. Fog hides your opponent's marks. Blitz rounds give you ten seconds to think. Double-turn levels flip the logic you just mastered.

BOSS BATTLES Every world ends with a boss that plays closer and closer to perfection. Beat it to unlock the next world — or lose three times and earn a helping hand.

POWER-UPS Ghost Stroke through crossed lines. Smash stones with the Breaker. Steal an extra turn with Second Wind. Jinx a perfect opponent into fumbling. Earn coins with every win to build your arsenal.

PLAY REAL PEOPLE, AT YOUR OWN PACE Send a friend a six-character code, or get matched with someone new. Games are turn-by-turn, so nobody has to be online at the same time — make your move, put your phone away, come back later. We'll tell you when it's your turn, so a game can run over a week without either of you remembering to check. Rematch anyone you've played, and earn coins for every win.

No email, no password, no sign-up. Pick a name and play.

PLAY YOUR WAY • Journey: the endless solo campaign • Play Online: a friend by invite code, or a stranger by quick match • Daily Challenge: one fresh puzzle a day — build your streak and score • Quick Match: pick your difficulty, from Easy to Perfect • Pass & Play: challenge a friend on one phone

FAIR BY DESIGN Hints show you a mathematically perfect move. Three stars only ever means you found the winning line yourself. No energy timers. Play as long as you like.

THE SOLO GAME NEEDS NO CONNECTION Every level, every opponent and the daily challenge all live on your device — perfect for flights, subways and dead zones. Online play is entirely optional, and the only thing it ever stores is the name you choose, an anonymous id, and the games you play. No ads, no tracking, no in-app purchases.

One more game. It only takes 30 seconds. That's how it starts.