Shaded Region Puzzles

• Similar to Object Placement Puzzles but where we shade areas in the grid. Areas are defined as containing possibly more than one cell.
• Typically shaded areas form regions that satisfy certain properties but distinct from Partitioning Puzzles where the color of the region is important.
• Overlaps with Connected Region Puzzles but here we do not require regions to be connected.
• Shading is not required. The spirit is to “mark” cells with a color.

Akiperago §

• Goal: Shade some cells in the grid
• Constraint: The black cells form “islands”. No two islands may share an edge. Islands may be connected through their corners.

• Constraint: If an island contains a numbered cell, this number represents the amount of black cells in the island.
• Constraint: An island may contain few numbered cells (all numbers will be the same inside an island).
• Constraint: All islands form “archipelagos”. An archipelago is a group of two or more islands, connected through their corners.
• Constraint: If an archipelago contains N islands, they will be from 1 to N cells (not necessarily in that order)

Chiyotsui §

• Goal: Shade some cells in the grid.
• Constraint: Black cells form areas. Each area spans exactly two regions.
• Constraint: The black areas are symmetrical with respect to a region border.
• Constraint: Cells with a number indicate how many cells in the region must be shaded.
• Constraint: No two black areas may share an edge.

Choco banana §

• Goal: Shade some cells on the grid.
• Constraint: Areas of black cells form a rectangle or square.
• Constraint: Areas of white cells must not form rectangular regions.
• Constraint: Numbers indicate area sizes.
• Constraint: An area may contain more than one cell with a number.

Chocona §

• Goal: Shade some cells in the grid
• Constraint: A cell with a number indicates how many cells in the region must be shaded.
• Constraint: Regions without numbers mean any number of cells may be blackened
• Constraint: Black cells must form rectangles independent of region borders.
• Constraint: Black rectangles are not orthogonally adjacent.

Dominion §

• Goal: Shade some cells in the grid.
• Constraint: Shaded cells form dominoes which can touch each other diagonally.
• Constraint: Cells with letters are unshaded
• Constraint: Cells with the same letter belong to the same region.
• Constraint: Unshaded regions must contain at least one letter.

Fill-a-Pix §

• Goal: Shade some cells on the board. The solved board will form a picture.
• Constraint: The cells with clues represent how many of the nine squares around it (including itself) should be filled in.

Kapama §

• Goal: Shade some cells
• Constraint: Create pairs of figures called twin shapes. Twin shapes are symmetrical with respect to the indicated diagonal line.
• Constraint: No shape may share an edge.
• Constraint: Cells with diagonal lines cannot be shaded.
• Constraint: Numbers indicate the number of black cells in the corresponding row or column
• Variant: Sunglasses - adds bridges which are not necessarily diagonal lines, and may be of any length. Twin shapes must be symmetrical with respect to the bridges. Bridges are never shaded.

Kuroclone §

• Goal: Shade some cells on the grid
• Goal: Each region must contain two areas of black cells.
• Constraint: Cells with numbers are always white.
• Constraint: Area pairs are of the same size and shape, potentially rotated or mirrored
• Constraint: Arrows in cells point to adjacent cells that belong to a black area.
• Constraint: Numbers in cells pertain to the size of the area pointed to by the arrow.
• Constraint: When two cells are orthogonally adjacent across region boundaries, at least one must be white.

Light and Shadow §

• Goal: Divide the grid into gray and white regions
• Constraint: Every region contains exactly one number
• Constraint: The region must have the same number of cells as the number it contains
• Constraint: Numbers in X colored cells are part of the region of color X
• Constraint: Same colored regions cannot share an edge.

Link-A-Pix §

• Goal: Shade some cells corresponding to lines drawn on the board. The solved board will form a picture
• Constraint: The cells with clues are the endpoints of a path and they represent the length of the path containing them (1 clues count as that cell being shaded.)
• Constraint: Both endpoints of a path must contain clues. All clues are given.
• Constraint: Paths may not cross

Miraringutairu §

• Goal: Locate blocks of black cells in the grid.
• Constraint: Numbered cells indicate the total number of black cells in the block
• Constraint: Blocks do not have to contain numbers.
• Constraint: Blocks cannot share edges.
• Constraint: Each block must be connected to another block of the same size and shape through their corners, subject to rotation or reflection.

Mochikoro §

• Goal: Shade some cells on the grid.
• Constraint: Shaded cells divide the grid into rectangular islands of unshaded cells.
• Constraint: Islands cannot share edges, but they must be connected diagonally via their corners
• Constraint: Islands must have the same number of cells as the number it contains.
• Constraint: No pools. No areas must contain only shaded cells

No Four in a Row §

• Goal: Fill the grid with symbols.
• Constraint: Four consecutive symbols never appear in any row, column, or diagonal.

Nondango §

• Goal: Shade some circles on the grid.
• Constraint: Each region contains one black circle.
• Constraint: Three consecutive circles of of the same color never appear in any orthogonal or diagonal direction. There must be a circle of the other color or an empty cell between them.

Norinori §

• Goal: Shade some cells in the grid
• Constraint: Every region contains exactly two black cells.
• Constraint: Each block must be a part of a domino, irrespective of region borders.
• Constraint: No two dominoes may share an edge. They can touch diagonally.

Nuribou §

• Goal: Shade some cells on the grid.
• Constraint: The black cells divide the grid in regions of white cells. Each region contains one cell with a number.
• Constraint: The number in the region gives the number of cells in the region.
• Constraint: Black cells form orthogonal stripes that are not orthogonally adjacent and are exactly one cell wide.
• Constraint: If two stripes are connected diagonally, the length of the stripes must be different

Santoitchi §

• Goal: Shade some cells in the grid
• Constraint: Numbered cells must not be shaded.
• Constraint: All white cells must be divided on regions having the size of exactly three cells.

• Constraint: Two black cells must not be orthogonally adjacent.
• Constraint: Each region contains a number.
• Constraint: A number indicates how many black cells share an edge with that region.

Shakashaka §

• Goal: Place triangles in some of the white cells.
• Constraint The white parts of the grid (that do not have black triangles) must form rectangular regions.
• Constraint: Black cells with a number must be orthogonally adjacent to the specified number of black triangles.

Shimaguni §

• Goal: Shade some cells in the grid.
• Constraint: All black cells in a region must be connected.

• Constraint: A cell with a number indicates how many cells in the region must be shaded.
• Constraint: In regions without a number at least one cell must be shaded.
• Constraint: Two regions with the same amount of shaded cells must not be orthogonally adjacent.
• Constraint:: When two cells are orthogonally adjacent across a region boundary, at least one cell must be unshaded.

Starry Night §

• Goal: Place one white circle (sun), one black circle (moon) and one star in every row and column of the grid.
• Constraint: Same figures may not touch each other diagonally.
• Constraint: Figures outside indicate the distance between the star and circles in that row or column.
  • White circle indicates the sun is closer to the star than the moon.
  • Black circle indicates the moon is closer to the star than the sun.
  • A star indicates that both sun and moon are equidistant.

Stostone §

• Goal: Shade some cells (i.e., place stones on the grid)

• Constraint: All black cells in a region must be connected horizontally or vertically.
• Constraint: A cell with a number indicates how many cells in the region must be blackened.
• Constraint: In regions without a number any amount of cells may be blackened (at least one).
• Constraint: When two cells are orthogonally adjacent across a region boundary, at least one cell must be white.
• Constraint: If all stones “fall down”, they must cover exactly the bottom half of the grid.

Tairupeinto §

• Goal: Shade some cells on the grid.
• Constraint: Each region is either completely filled or completely empty.
• Constraint: Numbers outside the grid indicate the number of shaded cells in that direction.

Trilogy §

• Goal: Fill the grid with figures.
• Constraint: Consecutive figures must not be all the same or all different in any row column or diagonal.

Trinairo §

• Goal: Fill the grid with letters so that each row and column has three A’s, three B’s and three C’s.
• Constraint: Marked cells have their letters differ from all other orthogonally adjacent cells.

Triplets §

• Goal: Fill each square with figures (square, circle, triangle)
• Constraint: Regions must either contain all identical or all different figures.
• Constraint: When two figures are orthogonally adjacent across a region boundary, the figures must be different.

Water Fun §

• Goal: Fill the grid with water
• Constraint: Numbers outside the grid show how many cells of each row and column are filled with water.
• Constraint: Connected areas of filled cells must have the same level of water everywhere