Shade each square black or white so every line is half and half and no three matching squares sit side by side.
Unruly Black and White is a neat two-color logic puzzle. Some squares on the grid start out black or white, and you need to color in the rest. Only two rules apply, but they work together in clever ways. Each row and each column must hold equal numbers of both colors, and no three squares in a straight line may match.
Lennard Sprong wrote this version for Simon Tatham’s collection, where it is named Unruly. Adolfo Zanellati invented the puzzle type and called it Tohu wa Vohu.
Getting started
Blank squares look gray. A left click colors one black, or right-click to color it white. Clicking again with the same button steps the square on to the other color and then back to empty, so any slip is easy to fix. Middle-click or Backspace clears a square straight away.
The starting squares have a small inner border and cannot be changed. On a keyboard, move with the arrows and use Enter or Space to color. U, R and N handle undo, redo and a new puzzle.
Rules in brief
Each line must be exactly split evenly between the two colors, which is why every grid has an even width and height. On an 8-wide row, that means four of each.
The second rule bans runs of three. Two whites side by side are fine, but a third white next to them is not. Breaking a rule makes the game flag it in red, with an outline for three in a row and exclamation marks when a line has too many of one color.
Winning moves
- Pairs are a strong clue. When two matching squares touch, the squares at both ends must be the other color.
- Gaps work the same way. If two squares of one color have one empty square between them, that middle square must be the opposite color.
- Keep counting. Once a line has its full share of one color, every empty square in it takes the other.
- When a line needs just one more of a color, check which empty squares would create a run of three of the other color.
- Switch between rows and columns often. Every square you fill in a row is also a new clue for its column.
Who it suits
This is a good pick for players who enjoy number-free logic puzzles with a clean look. The smallest preset, 8x8 Trivial, is gentle enough for a first try, while the 14x14 Normal grid and the unique-lines option give experienced solvers more to chew on. Seven presets are available, plus custom sizes, and undo and redo have no limit.
Controls
| Action | Keyboard | Mouse | Touch |
|---|---|---|---|
| Make a square black (then white, then empty) | Arrow keys to the square, then Enter | Left-click the square | Tap the square |
| Make a square white (then black, then empty) | Space | Right-click the square | Press and hold the square |
| Clear a square | Backspace | Middle-click, or keep clicking until it is empty | Keep tapping until it is empty |
| Undo, redo, new puzzle | U / R / N | Undo move, Redo move and New game buttons | Undo move, Redo move and New game buttons |
Unruly Black and White FAQ
Can I play Unruly Black and White on a phone or Chromebook?
Yes. Mouse, keyboard and touch all work. On a phone, tap once for black, or press and hold for white. Doing either one again moves the square to its next state.
How do I know when I have won?
The puzzle is solved once every square is filled, each row and column has equal numbers of black and white, and no line contains three of the same color in a row. Until then, red outlines and exclamation marks point out any problems.
What if I make a mistake?
Every square can be changed again except the fixed starting clues, and undo and redo have no limit. Use the U and R keys or the buttons. Red marks show broken rules, so you can usually spot a slip right away.
How do I make it harder?
Pick a larger preset, up to 14x14 Normal, or open Custom and switch on unique rows and columns. That extra rule means no two rows may share a pattern, and no two columns may either.
