Trichotomy

Published Mar05 2025.

Update (Mar05 2025): tweaked puzzle Swivel, per Zimodo's suggestion.

Update (Mar09 2025): added puzzle Flout.

Update (Jan12 2026): renamed genre to Trichotomy.

Summary

Shade cell groups with three neighbors each.

Rules

Shade some cells, forming orthogonally adjacent groups of shaded and unshaded cells.

• Black circles are shaded, and white circles are unshaded.
• Groups contain at most one circle.
• All shaded groups are orthogonally adjacent to exactly three unshaded groups.
• All unshaded groups are orthogonally adjacent to exactly three shaded groups.

Puzzles

1. Swivel
2. Brazier
3. Giddy
4. Flout