Puzzle types
The rules of every puzzle on the site, each with pictures of what works and what doesn’t, and a worked example.
Lines
- Masyualso PearlDraw one loop through cell centres that goes straight through white pearls and turns on black ones.
- Number Line MazeDraw the walls each number asks for, then find your way from the arrow in to the arrow out.
- Numberlinkalso Connectlink, Flow, ArukoneJoin each pair of matching numbers with a line; lines never cross.
- Simple Loopalso Round the BendDraw one loop that winds through every white cell.
- Simple Pathalso Hamiltonian PathDraw one path from the arrow in to the arrow out that visits every white cell.
- Slitherlinkalso Fences, Loop the LoopDraw one loop along the dotted lines; each number counts the sides of its cell the loop uses.
Shading
- Akarialso Light UpPlace light bulbs so every white cell is lit and no bulb shines on another.
- AquariumFill the outlined tanks with water that settles level; the numbers count the water in each row and column.
- Cavealso Corral, BagShade the rock around one connected cave; each number counts the cave cells it can see.
- HitoriShade cells so no number repeats in a row or column; shaded cells never touch, and the rest stay connected.
- MinesweeperEvery number counts the mines in the eight cells around it.
- Nonogramalso Picture Squares, Griddlers, Paint by Numbers, PicrossShade the cells the numbers ask for to uncover a hidden picture.
- Nurikabealso Islands in the StreamShade a winding wall so every number sits in a white island of exactly that size.
- Star Battlealso Two Not TouchPlace one star in every row, column and outlined area; stars never touch.
- Wittgenstein Briquetalso Desk PlacePlace straight blocks of three; numbers count block cells beside them, and the rest stays connected.
Regions
- PanesCut the window into panes of stained glass that follow every rule listed with the puzzle.
- Shikakualso Rectangles, Divide by BoxCut the grid into rectangles, each holding one number: its size.
- Spiral Galaxiesalso Tentai ShowSplit the grid into regions that look the same turned halfway round their circle.
- Square JamSplit the grid into squares; four never meet at a point, and a number is its square's side.
Numbers
- Easy as ABCalso Letterraam, End ViewPut each letter once in every row and column; letters outside are the first one seen.
- Irregular Sudokualso Jigsaw SudokuA sudoku whose boxes are odd shapes: every row, column and outlined area has each digit once.
- Skyscrapersalso TowersFill in building heights; the numbers outside count the buildings you can see.
- SudokuFill the grid so every row, column and box has each digit once.
- Thermo SudokuA sudoku whose digits rise along each thermometer, from the bulb to the tip.