Pipes gives you a square grid full of pipe pieces, each pointing the wrong way. Turn them until they all join into one network fed from the source in the middle, with no loose ends and no loops. Every board is built from a real solution, so there is always a way to connect it.
The rules
Every square holds one piece: an end, a straight, a corner or a T-junction.
Tap a piece to turn it a quarter turn clockwise. Each turn counts as a move.
Water flows from the source (the ringed piece in the center) into every piece joined to it.
You win when water fills every piece: each pipe end meets another, none points off the board, and there are no loops.
Controls
Hold a piece to lock it once you are sure it is right. Locked pieces are shaded and will not turn; hold again to unlock.
Undo takes back your last turn or lock.
On a keyboard, use the arrow keys to move, Space or Enter to turn, Shift+Space or Q to turn back, L to lock and Ctrl+Z to undo.
Start at the edges
Pieces on the border have fewer ways to face, and corner squares fewest of all. A straight on the edge must run along it, a T on the edge must keep its stem pointing inward, and a corner in a board corner can only face one way. Fix these first and lock them.
Each locked piece tells you which way its neighbors must open, so the solved area spreads inward from the edges.
Useful deductions
Two end pieces never point at each other: they would form a pair cut off from everything else.
If a piece already faces a side with no opening, that side is closed, so its neighbor must turn away from it.
Watch the water: if a branch fills but a nearby piece stays gray, the gap between them is your next move.
A closed loop can look connected, but it is never part of the answer. Break it by turning one piece in the loop.
Boards and records
Easy is a 5×5 grid, Normal 7×7 and Hard 9×9. The clock starts with your first turn, and your best time and number of puzzles solved are kept separately for each board.