1A2B — Bulls & Cows

The classic Bulls & Cows number game. Learn it in 30 seconds. A new puzzle every day, same for everyone — build your streak and challenge your friends!

Remember playing this with a pencil in the back of class? Each of you hides a secret number, trading guesses turn by turn — first to crack the other's code wins. That game now lives in your pocket.

The rules take 30 seconds: A = right digit, right spot; B = right digit, wrong spot. Use those two clues to crack the secret number in as few guesses as you can. Simple rules, pure deduction, minutes a round.

— DAILY CHALLENGE One puzzle a day, the same for everyone worldwide. Build your streak and share your result with friends.

— 3 TO 10 DIGITS Start easy with 3 digits or push your limits at 10. From casual to hardcore.

— PENCIL & PAPER TOOLS, BUILT IN The best part of 1A2B has always been scribbling notes while you deduce — so we built it in: • Digit marks: one tap crosses out digits you've ruled out, or circles the ones you know are in • Position notes: jot candidate digits for every slot and narrow the answer down step by step • Notes save automatically with each game — leave and pick up your deduction right where you were

— AND MORE • Full guess history — see every step of your deduction • Stats and win rate to track your progress • Hand-drawn notebook feel, like deducing on real paper • Fully playable offline — commutes, queues, bedtime

Ready? Today's number is waiting.