Sudoku
A classic 9×9. Put 1 through 9 in every row, column, and box.
Killer Sudoku
A 9×9 Sudoku whose cages must sum to the printed totals. Digits do not repeat in a cage.
Binary Puzzle
Fill the grid with two symbols. Each row and column is balanced, has no three in a row, and is unique.
Futoshiki
Place 1–N once in every row and column, while respecting the inequalities.
Kakuro
Fill each run with distinct digits 1–9 so they add up to its clue.
Codebreaker
Crack the hidden code using exact and misplaced digit clues.