Pipes 20×20: the huge board
Four hundred tiles, the biggest board on the site. Best on a large screen; on a phone, zoom the page or turn it sideways.
It is the same logic as on the small boards, just more of it: edges first, then loops and islands, and pins everywhere you are certain.
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 or Enter 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.