The board and the clues
- Nonogram
- A logic puzzle in which numbers beside each row and above each column describe a hidden picture. You reveal the picture by deciding, for every cell, whether it is filled or empty. The same puzzle is also published under names such as Picross, Griddlers and Hanjie.
- Grid (board)
- The rectangle of cells you solve. Nogramix boards are square: Spring Forest has 5×5, 7×7, 10×10 and 15×15 puzzles, and the Daily Nonogram is 7×7 on Monday and Friday, 10×10 from Tuesday to Thursday and 15×15 at weekends (UTC).
- Cell
- One square of the grid. In the finished picture every cell is either filled or empty.
- Line
- A single row or column. Each line has its own clue, and most solving happens one line at a time.
- Clue
- The numbers beside a row or above a column. They give the lengths of the filled runs in that line, in order. A clue of 3 1 means a run of three filled cells, then a run of one, with at least one empty cell between them.
- Block (run)
- A group of consecutive filled cells described by one number of a clue.
- Gap
- The empty cells between two blocks of the same line. Blocks from one clue are always separated by at least one empty cell.
- Zero clue
- A clue of 0: the line has no filled cells at all, so every cell in it is empty.
| 3 3 | × | × | × | × |
|---|
Cell states
- Filled cell
- A cell proven to be part of the picture.
- Mark (×)
- A cell proven empty. The × records that proof; it is not part of the picture. See what an × means in a Nonogram.
- Unknown cell
- A cell that is not decided yet. Leaving it blank is fine. Filling or marking it without a reason is a guess.
- Finished line
- A line whose blocks are all placed. Any unknown cells left in it are empty and can be marked.
Solving terms
- Line logic
- Solving one line at a time: from a line's clue and the cells already known, find every cell that is filled, or empty, in every possible placement. Repeated over all rows and columns, it finishes many well-made puzzles on its own, including every Spring Forest puzzle in Nogramix.
- Overlap
- The cells a block covers both when it is pushed as far as possible to one end of the line and as far as possible to the other. Those cells are filled in every placement. See the Nonogram overlap technique.
- Slack
- How far the blocks of a line can slide: the line length minus the space the clue needs (the numbers plus one gap between each pair). A block longer than the slack always has overlap cells.
- Reach
- The cells a block could possibly cover. A cell that no block can reach must be empty.
- Edge (wall)
- The border of the grid, or a cell already proven empty. A filled cell close to an edge limits how far its block can extend, which often forces more cells.
- Contradiction
- A reasoning step for when line logic stalls: suppose a cell is filled, or empty, and follow what that forces. If a clue becomes impossible, the opposite is proven. See the contradiction technique.
- Unique solution
- The clues fit exactly one picture. Nogramix checks this for every Spring Forest puzzle and every Daily Nonogram. Uniqueness alone does not mean line logic is enough.
- Guess
- Filling or marking a cell without proof, and hoping it works out. A puzzle with a unique solution never requires one.
Try the terms in Spring Forest