QUARTURN

Rotate the circuits. Light every bulb.

The goal

Every board is one connected circuit that has been scrambled: each tile was spun by a random number of quarter turns. Power flows out of the source tile (the lightning bolt) through any wires whose ends meet. Turn tiles until power reaches every bulb. Nothing else counts; there is no time limit, only your time and move count.

Controls

• Tap or Click a tile: rotate a quarter turn clockwise.
• Shift+click (or Alt+click): rotate the other way.
• Right-click or long-press: lock a tile you are sure about. Locked tiles do not turn.
• Z: undo the last turn. H: hint. Esc: close panels.

Reading the board

• Bulbs are dead ends with one connection. They light up when powered.
• Wires have two or three openings. A straight wire looks the same after two turns, so you may need fewer moves than you think.
• Every solution is a single tree with no loops: no two wires ever connect twice to the same place.
• Start from the edges. An edge tile can never point off the board (unless Wrap is on), which usually fixes its orientation at once.

Hints and undo

A hint briefly highlights one misaligned tile next to the powered network. Hints are counted and shown on the win screen, so a clean solve stays a clean solve. Undo reverts the last turn and counts as a move.

Board sizes, Wrap and the Daily board

Pick Easy (5×5), Medium (7×7), Hard (9×9) or Expert (12×12). Turn on Wrap and the board becomes a torus: wires can leave the right edge and come back on the left, so edges no longer give anything away. The Daily board is one shared 7×7 for everyone, changing at midnight UTC, with a leaderboard of the fastest solves. Solve it on consecutive days to build a streak; miss one day a week and the streak survives, and yesterday's board can be played to repair a gap. Solve it on consecutive days to build a streak; miss one day a week and the streak survives, and yesterday's board can be played to repair a gap.

Sharing and saving

Every board has a seed in its link, so you can send a friend the exact puzzle you just solved. Play as a guest and your best times sync to a private profile; link a Google account later to keep them across devices.

More: Easy · Medium · Hard · Expert · Challenges · About · Changelog