THE LOGIC COLLECTION / No. 01

Magnet Atelier+ −

A little attraction. A little deduction.

THE CHALLENGE

Opposites belong together.

Every outlined pair is either a magnet + − or a neutral domino · ·. Fill every pair to match the edge counts.

Equal poles must never touch along an edge. Diagonals are fine.

+Coral counts: positive poles

−Blue counts: negative poles

Puzzle

How to play

Click a square: put + here, then −, then clear. Choose Neutral to mark an empty pair. Right-click also marks neutral.

Keyboard: arrows move, Enter cycles poles, Space marks neutral. Z undoes. Your progress saves in this browser.

Hints reveal one pair from the original engine's solution. A dot is a decided neutral pole; ? is undecided.

Clues show placed / needed. Green means the count matches.

Adapted from Simon Tatham’s Magnets · James Harvey · MIT source license · 18 quiet logic studies