Half-fill cells with diagonal triangles until the clues are satisfied and the white that remains has settled into tidy rectangles.
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How to play
Black cells, some carrying a number, are fixed. Drop right-triangles into the white cells so two conditions hold together, leaving a single solved board you reach by logic.
Each numbered black cell must have exactly that many triangle-filled cells among its orthogonal white neighbours.
Every connected region of leftover (untriangled) white must form a perfect rectangle.
A triangle fills one diagonal half of a cell; pick the orientation that fits the shapes around it.
Numbers turn green when satisfied and red when overshot; the board completes when both rules hold everywhere.
Controls
Desktop: click a white cell to cycle through the four triangle corners and back to empty; right-click steps backwards through the orientations.
Phone & tablet: tap a white cell to rotate the triangle through its four orientations and clear it; black numbered cells are fixed and ignore taps.
Game modes
Daily: a single 5x5, 6x6 or 7x7 puzzle shared by all players each day.
Practice: unlimited freshly generated boards.
A live status line tracks triangles placed and clues satisfied as you work.
Tips & strategy
Start at a clue of 0, none of its white neighbours can hold a triangle, which locks several cells immediately.
Picture the rectangles first: a leftover region that is L-shaped or jagged can never be valid, so add a triangle to square it off.
Corners with a single white neighbour force that neighbour's count, giving you a foothold.
Origins
Two clue traditions meet here, and neither is the puzzle's whole rule set. Counting how many neighbours of a numbered cell are filled is the clue style of Minesweeper; requiring leftover space to resolve into clean rectangles is the idea behind Shikaku, the Nikoli puzzle whose object is dividing a grid into boxes.
The combination appears to be this game's own. A numbered black cell counts the triangle-filled cells among its orthogonal white neighbours, and every connected region of untriangled white must form a perfect rectangle.
Those two rules constrain each other in a way neither does alone. Satisfying a count is a local decision, while the rectangle rule is global — an L-shaped or jagged leftover region can never be valid — so the usual move is to add a triangle purely to square off a region, which the counting clue then has to accommodate.
About Half-Shade
Half-Shade is an original geometric logic puzzle that blends number-clue deduction with shape-fitting, rendered on a clean canvas board. It is free to play in your browser with daily and endless modes and nothing to install.
A free, original browser game on PlayPendium. No download, no install.
