Theme: Pairs
Rules: Shade some cells so that all shaded cells are connected and no 2×2 square is completely shaded. Cells with numbers cannot be shaded. Each group of connected unshaded cells forms an island; islands can touch each other diagonally. Each island must contain exactly one given number that indicates the number of cells inside the containing island.
Theme: Odd vs Even
Rules: Shade some cells so that all shaded cells are connected and no 2×2 square is completely shaded. Cells with numbers cannot be shaded. Each group of connected unshaded cells forms an island; islands can touch each other diagonally. Each island must contain exactly one given number that indicates the number of cells inside the containing island.
Rules: Divide the grid along the gridlines into some regions, and fill each of the empty cells with a number. When two cells containing the same number touch along an edge, they must belong to the same region. Given numbers represent the area of the region they belong to. A region may contain none, or one or more of the givens. Also, every region must be adjacent to a region of consecutive size.
Rules: Shade some cells such that each given tells how many cells sharing a border with it are shaded. No two shaded cells can share borders. Then draw a single, non-intersecting loop, vertically or horizontally, through the centers of all of the empty cells. Given clue cells cannot be shaded.
Rules: Shade some cells such that each outlined region contains two or more groups of orthogonally connected shaded cells of the same size but different shapes. There cannot be any other shaded cells. Shaded cell groups across regions can only touch diagonally, while they must all be connected to each other diagonally within a region. Given numbers indicate shaded cells part of a group of that size. Each group contains one or no given number.
.PNG)
Rules: Shade in some cells such that each outlined area contains eight shaded cells that form two tetrominoes. No 2×2 square can be shaded completely. Tetrominoes within a region cannot touch through the edges. All shapes must be connected to form a single contiguous group of shaded cells. Identical figures, regardless of rotation or reflection, cannot share an edge.
Rules: Shade in some cells so that all shaded cells are orthogonally connected through the clue cells in a single group, or the Island. Numbers in clue cells indicate the number of shaded cells that can be reached from the clue cell without crossing other clue cells or white cells.