Pipes puzzle
Rotate the tiles so that water from the pump reaches every lamp. All the pipes must join into one network: no open ends and no closed loops.
Every puzzle has exactly one solution, and you can find it step by step, by reasoning rather than by trying turns at random. How to play shows the techniques that crack the hardest boards.
Rules
Click a tile to rotate it. The puzzle is solved when the pipes form one network from the pump to every lamp, with no pipe pointing at nothing and no closed loop. Water shows how far the pump reaches, and the counter above the board shows how many lamps are lit.
Mouse and keyboard
- Click: rotate clockwise; Ctrl+click: rotate back.
- Right click: pin a tile you are sure of; a pinned tile does not rotate.
- Keyboard: arrows move the cursor, Space rotates, P pins, Ctrl+Z and Ctrl+Y undo and redo.
Touch screen
- Tap: rotate.
- Long press: pin a tile.
- The Pin button under the board swaps the two: a tap pins, a long press rotates.
Difficulty
Easy puzzles fall to simple steps from the edges. Normal ones are chosen so that the edges are not enough: two or three times you get stuck and need an insight about loops or closed groups, and each insight unlocks a stretch of the board. Hard puzzles add steps that need a short what-if. On every level the solution is unique and found without guessing.
Wrap around and colours
Two switches in the menu change the rules. With Wrap around opposite edges are joined, and the board has nowhere easy to start. With Colours there are several pumps: each must reach the lamps of its own colour, and networks of different colours must never touch. The pipes are grey until water reaches them, so working out which pipe belongs to which network is part of the puzzle.