Every jack carries a bulb. One press flips the bulb and its four neighbours. Match the wall to the duty slip.
Board 17 · wall finding the pattern
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Contains ads · Rewarded video.
No account, no payment · all 24 boards are free.
Board wall24 boards · three chapters
Rings 0
First reliefBoard 1 · Chapter I
Presses 0/2Left 5
Duty slip · match this
All bulbs dark
Pressing a jack flips it and its four neighbours.
litdarkcross-wireddead jackcord on jack = already pressed
Rules of the floor
The press
Tap a jack to press it. A press flips its own bulb and the bulbs of the four jacks next to it (up, down, left, right). Edge jacks have fewer neighbours, so they flip fewer bulbs. Flipping means on becomes off and off becomes on.
Order never matters. What matters is which jacks you press, and each jack you press twice is a press wasted.
Cross-wired jacks
A jack with a crimson ring is soldered across: it flips its four neighbours and the four diagonals as well. Note that the diagonal partner does not answer back — a crossover is a one-way habit.
Dead jacks
A jack with a grey ring is a burnt contact: pressing it flips the neighbours but not its own bulb. Dead jacks are the trick of the third chapter.
The duty slip
The paper card shows the pattern the wall must end in. Dark means the bulb stays off. Some slips ask for all bulbs dark, others spell a message pattern.
Scoring
Par is the proven shortest press count: the wall is a linear system over GF(2), solved by elimination and by trying every member of its kernel. Nothing is guessed.
Par earns three stars, par + 2 earns two, anything else one.
Each board also has an allowance of par + 5 presses; past that the call is lost, and a spare cord buys two more.
A hint marks one jack from the proven set. Hints are free and unlimited.
Ads
Every AD button is a full rewarded film you may skip at any time, and each one can be watched again as often as you like. No board, hint or retry here is locked behind an ad.
Board closed
Chapter I · First relief
0presses · par 0
HELD
The floor is held
Bulbs, presses and the ring box are frozen while the film plays. Nothing moves until you are back at the wall.