Diagonal

Diagonal is a fast, strategic board game you can learn in 30 seconds and replay for hours. Connect, block, and outmaneuver your opponent on a beautifully minimal board. Every move matters. Every game is different.
Whether you want a quick brain workout on your commute, a tiebreaker with a friend across the table, or an online strategy duel with someone halfway across the world, Diagonal fits the moment.

THREE WAYS TO PLAY

Single Player vs AI
Sharpen your strategy against an AI opponent that adapts to your skill level. Start easy and work your way up to expert. The AI gets smarter as you do, so you will never run out of challenge.
Play in Person (Local 2 Player)
Pass the phone and settle the score. The fastest way to find out who really has the sharper mind, perfect for the dinner table, road trips, flights, or anywhere you have a friend and a few spare minutes.
Play with Friends Online
Create a private online room, share the code, and challenge anyone, anywhere. No accounts to set up, no friend lists to manage, no waiting for matchmaking. Just send the link and play.

WHY PLAYERS LOVE DIAGONAL

Easy to learn, hard to master: one core rule, no tutorial overload
Fast matches: most games end in under 3 minutes
Beautifully minimal design with zero clutter
Plays offline: single player and pass-and-play work without internet
No grinding, no energy timers, no pay-to-win mechanics
Quick rematches with a single tap
Adaptive AI difficulty from beginner to expert
Private online rooms with shareable codes

DESIGNED FOR REAL LIFE

Diagonal fits the gaps in your day. Waiting for the bus. In line for coffee. Stuck on hold. The kind of strategy game you open for one quick match and look up 20 minutes later wondering where the time went.

PERFECT FOR
Strategy and chess fans who want something faster paced
Puzzle and brain game players looking for real competition
Couples and roommates who need a tiebreaker
Long-distance friends staying in touch through play
Commuters and travelers who want offline games that respect their time
Anyone bored of slot-machine style mobile games

A SIMPLE GAME WITH INFINITE DEPTH

Like the best board games, Diagonal works because the rule is simple but the strategy is endless. Every position has a perfect move, if you can find it. Every game teaches you something for the next one.
Download Diagonal free and play your first match in under a minute.