HEXDOKU.COM

Hexdoku is a variation on Sudoku puzzles; however, instead of using just the numbers 1-9, Hexdoku uses a form of hexadecimal using the numbers 0-9 AND the letters A-F, where A=10, B=11, C=12, etc., making it a bit more difficult to play. Sudoku uses a 3-by-3 grid of boxes, where Hexdoku uses a 4-by-4 grid.

• Click any white cell to select it
• Use arrow keys (↑ ↓ ← →) to navigate - automatically skips pre-filled cells
• Type 0-9 or A-F to fill the cell (or use the on-screen keyboard)
• Press Delete/Backspace to clear a cell
• Fill each row, column, and 4×4 block with all 16 symbols (0-F)
• Blue cells are pre-filled and cannot be changed