Over these last few weeks I’ve returned to my roots with a few Killer Sudoku variants, which I recently posted to the Daily League on Facebook. I have a few more ideas, but they’ll have to wait until after finals.

### Star Battle Killer

Place the numbers 1-8 and two stars in each row, column, and jigsaw group. Stars cannot touch each other, even diagonally. Numbers cannot repeat within cages. Stars count as 0 in cages.

### Butterfly X Nurikabe Killer

This puzzle is made up of four overlapping 9×9 Sudoku grids arranged in a butterfly pattern (1 in each corner), each with it’s own set of main diagonals, which must contain the numbers 1-9. The sum/size of all cages are given, but not their shapes. The shapes of cages must form islands in a valid Nurikabe solution. Givens are shaded, and thus cannot be part of a cage.

### Killer Battleships

Classic Sudoku rules apply. Additionally, a fleet of battleships must be placed into the grid, such that they do not touch, even diagonally. Cells occupied by the battleships must add up to the sum associated with each ship, and any cell sharing an edge with a ship cannot contain any of the numbers inside the ship. Numbers on the outside of the grid indicate how many cells in that row or column are occupied by a ship. Givens are “sea” squares, and cannot contain a ship.