# Puzzle 153: Friendly Sudoku

Here’s a new (?) Sudoku variant. Inspired by Sudoku N from the upcoming Sudoku Mahabharat. The 6×6 example there also solves uniquely by these rules.

Rules Solve as a regular Sudoku. Some pairs of numbers are friends. Dots mark all spots where two friends are next to each other.

# Puzzles 138-140: Not Oasis

I played around with what I thought were the rules to Oasis today, and came up with this variant.

Rules Shade some cells, to leave a connected area of unshaded cells that includes all given numbers and doesn’t cover any 2×2 square. Some shaded cells are given. Numbers indicate how many other numbers can be reached through unshaded, unnumbered cells.

Example (a poor example: shaded cells can be adjacent)

Puzzles

# Puzzle 137: Lamps

Just a tiny puzzle that I made as an example for the croco WPC preparation series. It was a bit too hard as an example; the type seems inherently hard.

Rules Place some lamps in the empty cells around the grid, with brightness 0 to 3. The lamps shine horizontally, vertically and diagonally in eight directions. In each direction, they illuminate as many cells as they are bright. Numbers inside the grid indicate how many lamps illuminate the corresponding cell.

The WPC instruction booklet has an example.

# Puzzle 132: Illumination

Here’s something new, though I wouldn’t be entirely surprised if someone did this before. There’s an example below.

Edit The example was buggy, should be fixed now.

Rules Place some light sources and walls. Light sources go on grid vertices, but not on the border. Walls go on grid lines and must not touch light sources. Numbers outside the grid indicate how many light bulbs illuminate the adjacent edge in total, where a light bulb that illuminates the entire edge counts for 1 (regardless of distance), a light bulb that illuminates the edge partially counts for the corresponding fraction.

Example

# Puzzle 100: Keller, Mosaik+Labyrinth

Here’s a puzzle for one of the types on the Keller round, with superimposed puzzles.

Rules Solve the left grid as a Mosaik. That is, shade some cells, such that each number indicates the number of shaded cells in the surrounding cells, including the cell itself (so, 9 is the maximum clue). Solve the right grid as a Magic Labyrinth with digits from 1 to 3. That is, place digits 1, 2, 3 in some cells such that every row and column contains each digit exactly once, and walking along the labyrinth from outside to inside, you visit digits in the repeating order 1,2,3,1,2,…, starting with 1.

The two puzzles interact: Whenever a Mosaik clue is shaded, copy that clue to the Labyrinth in the corresponding position.

# Puzzle 85: Nanro Signpost

One more Nanro Signpost.

Rules Shade some cells, so that all shaded cells are connected, and such that shaded cells don’t fill any 2×2 square. Clues indicated the number of shaded cells in an area; each area must have at least one shaded cell. Whenever two shaded cells touch across walls, the number of shaded cells within both areas must be different.

Or see the instruction booklet, with a somewhat different formulation of the rules.

# Puzzle 84: Nanro Signpost

One more practice puzzle, a Nanro Signpost.

Rules Shade some cells, so that all shaded cells are connected, and such that shaded cells don’t fill any 2×2 square. Clues indicated the number of shaded cells in an area; each area must have at least one shaded cell. Whenever two shaded cells touch across walls, the number of shaded cells within both areas must be different.

Or see the instruction booklet, with a somewhat different formulation of the rules.