One Lie

About One Lie

One Lie is a free browser puzzle that launched on 18 September 2026. Each case hides a code, three digits on Easy and four on Medium and Hard, with every digit from 1 to 6 and repeats allowed. You get a short list of statements about it, such as the digits add up to 10, position 3 is a 6, or the digit 3 appears exactly twice. All of them are true except one.

The way in is to take each statement in turn and ask whether the others still agree on a single code if that one is the lie. Only one statement survives the test, and the code it leaves is the answer. The maker checks every case by brute force against all 1,296 possible codes, so exactly one code breaks exactly one statement and no guessing is needed. Easy and Medium lean on statements about single positions, while Hard brings in arithmetic across the whole code.

When you enter a code and press Accuse, the board tells you how many positions are right and how many statements your guess breaks, but not which ones. The right answer breaks exactly one. Easy allows three attempts, Medium and Hard two, and when they run out the answer and the lying statement are shown. A scratchpad under the statements has a grid for crossing off digits by position and a notepad, kept on your device.

The daily case is the same for everyone in the world, built from the date, and turns over at midnight New York time. The three modes are scored separately, with a daily leaderboard, a streak and statistics kept in your browser. Past cases are in the archive with their answers blurred, and twenty practice warm-ups with two-digit codes teach how it works. There is no account, no payment and no advertising.

How to play One Lie

1. Open playonelie.com and pick Easy, Medium or Hard for today's numbered case.
2. Read the statements about the hidden code; each digit is 1 to 6 and digits may repeat. Exactly one statement is false.
3. Test each statement as the lie: if the others then agree on one single code, you have found the liar and the answer.
4. Enter the code and press Accuse. The board shows how many positions are right and how many statements your guess breaks.
5. Solve within three attempts on Easy or two on Medium and Hard, then try the other modes.

Screenshots

Tips

• Look for two statements that cannot both be true: one of them must be the lie, so every other statement is true.
• If your guess breaks zero statements, it is too perfect to be right; the answer always breaks exactly one.
• Use the scratchpad grid to cross off digits position by position as the true statements rule them out.
• Start with the Practice warm-ups, two-digit codes with three statements, before trying Hard.

Questions