Black Ring White Ring
Black Ring White Ring is a variation of the standard Ring Ring puzzle, first introduced by Pavel Yarkin in September 2025 as part of the Ring-Ring Rally contest.
The idea emerged during a discussion with Alexandra Nazarova about a potential new variant called “Squares and Rectangle Rings,” which later developed into the form now known as Black Ring White Ring. The concept was initially postponed with a remark that it “needed some drawing,” along with the suggestion that Pavel should become the author of this variant.
In Black Ring White Ring, the puzzle features two distinct types of loops. The only difference between them is structural:
- Black rings must form perfect squares,
- White rings may form rectangles of other proportions.
This simple geometric distinction produces elegant logical consequences: the solver must weave square and rectangular loops through the grid so that all constraints of the Ring Ring framework are maintained, while respecting the shape restrictions of each loop type.
The idea emerged during a discussion with Alexandra Nazarova about a potential new variant called “Squares and Rectangle Rings,” which later developed into the form now known as Black Ring White Ring. The concept was initially postponed with a remark that it “needed some drawing,” along with the suggestion that Pavel should become the author of this variant.
In Black Ring White Ring, the puzzle features two distinct types of loops. The only difference between them is structural:
- Black rings must form perfect squares,
- White rings may form rectangles of other proportions.
This simple geometric distinction produces elegant logical consequences: the solver must weave square and rectangular loops through the grid so that all constraints of the Ring Ring framework are maintained, while respecting the shape restrictions of each loop type.
Rules
Draw few rectangular loops through the centers of unshaded cell so that every unshaded cell is used. The sides of different rectangles may intersect each other, but not turn at their intersections or otherwise overlap. Each given circle should be in a corner of a rectangle. If the circle is black, then the corresponding rectangle must be square. If the circle is white, then corresponding rectangle can not be square.
Click to see the answer.