How to play
Every visit hands you a chess position taken from a real game, always with the side to move at the bottom of the board. Look at it for as long as you like, then play the one move you think is best: click a piece and click its destination, or drag it. The move is graded at once against every other legal move in the position, you see how much it cost or gained in winning chances, and the best line is shown on the board. Then the next position arrives. There is no clock, no opponent and no game to finish — the only thing that counts is the quality of the move you just made.
Grades
Each legal move in a position was evaluated in advance by the Stockfish engine, and the evaluation is converted to a winning percentage on the same scale Lichess uses for accuracy. Your grade is how much winning chance your move gave up compared with the best move.
| Grade | Chance lost | Points |
|---|---|---|
| Best | none — the engine's first choice | 100 |
| Excellent | under 2% | 90+ |
| Good | under 5% | 80+ |
| Inaccuracy | under 10% | 60+ |
| Mistake | under 20% | 20+ |
| Blunder | 20% or more | 0+ |
A checkmate counts as a 100% winning chance, so missing a forced mate is scored the same as throwing away a winning position.
Modes
- Quick play — an endless stream of random positions. Pick a difficulty and keep going; your session average is shown in the header and your lifetime statistics are kept in this browser.
- Daily 10 — the same ten positions for everyone each day, from easy to hard. Finish the set for a score out of 1000 and a result card you can copy and compare. Playing on consecutive days builds a streak.
Difficulty
Positions come from the Lichess puzzle database, which rates every puzzle by how often real players find its solution. Easy positions are rated up to 1200, medium ones between 1200 and 1800, and hard ones above 1800. The rating of the current position is always shown above the board.
Tips
- Check the forcing moves first. Checks, captures and threats — in that order. Most positions here have a point, and it usually begins with a forcing move.
- Ask what changed. The position is shown right after your opponent's last move, which is highlighted. That move left something behind — a loose piece, an open file, an undefended square. Find it.
- A safe move is not a free move. Quiet developing moves often score as inaccuracies simply because a stronger move was available. Aim for the best move, not the safest one.
- Read the result. The panel shows the best line and the top alternatives with their evaluations. A minute spent on why a move was better is worth more than the next puzzle.
About Passant
Passant takes its name from en passant, the French for "in passing" — a chess rule, and also how this game is meant to be played: drop by, make one move, and move on. Positions are drawn from the Lichess open puzzle database, released under the CC0 licence, and every legal move in each position was evaluated in advance with Stockfish, so grading is instant and identical for every player. The piece set and board were drawn for this game.