Pixel Logic

On a computer, click a square to fill it and right-click to cross it out. Hold the button and drag to paint a whole row or column in one go. You can also play from the keyboard: the arrow keys (or W, A, S, D) move, Space fills, X crosses, and holding Shift while you move keeps painting. T switches between fill and cross, U undoes, H gives a hint and C turns Check on or off.

On a phone or tablet, tap to fill and press and hold to cross out. Drag your finger to paint a line. The Fill/Cross toggle under the grid switches what a tap does, and Undo, Hint and Check sit beside it.

Pick a board from the menu: Pictures or Random, each in 5×5, 10×10 or 15×15. New moves on to the next board and Daily opens today’s shared puzzle. The small thumbnail in the corner shows your picture so far.

1. Each clue is the length of one run of filled squares in that line, listed in order from left to right or top to bottom.
2. Runs in the same line are separated by at least one empty square.
3. A line with a 0 clue has no filled squares at all.
4. Crosses are notes for yourself; they are never required.
5. You finish when every filled square matches the clues. A clue dims once its line is correct.
6. Your score is your time. Lower is better, and each board size and mode keeps its own best.

Start with the big numbers. In a 10-square row, a clue of 8 must cover the middle six squares wherever it sits. Add up a line’s clues plus the gaps between them; the closer that total is to the line length, the more squares you can fill straight away.

Fill zeros and full lines first. A 0 means cross out the whole line. A clue equal to the line length means fill all of it. Both give the crossing lines a head start.

Cross out what can’t be reached. Once a run is complete, put crosses on both ends. Squares too far from any possible run position can be crossed as well.

Work back and forth. Every square you settle in a row is new information for its column. Sweep the rows, then the columns, and repeat.

Use the edges. A filled square touching the border pins the first run in place: a 3 starting at the edge fills exactly three squares and then needs a gap.

Let the clues dim for you. When a line’s clue fades, its filled squares match. Cross out the rest of it so you don’t have to think about it again.

Grid pictures drawn from number clues were published in Japan in the late 1980s, when puzzle designers Non Ishida and Tetsuya Nishio created similar puzzles independently. The British newspaper that ran them from the early 1990s named them nonograms after Ishida. They spread worldwide under many names, including griddlers, paint by numbers and hanjie, and a well-known handheld series called them Picross. Mathematically, solving them in general is NP-complete, but well-made puzzles can always be cracked one line at a time. Pixel Logic is ArcadeWren’s own version, with original pictures, its own look and boards checked for a logical path.

• Daily board. One 10×10 board a day, the same for every player, so you can compare times.
• Big boards. 15×15 grids with long clue lists, where the edge and overlap tricks really pay off.
• No-check runs. Turn Check off and finish without a single correction.
• Colour puzzles. Versions with several colours and coloured clues, which ArcadeWren may add later.