How to Play Easy Killer Sudoku
To solve Easy Killer Sudoku, you must fill in the grid following standard Sudoku rules plus additional cage constraints:
- Place numbers 1–9 in each unit (row, column, or 3x3 block) without repeats.
- Cages are outlined by dotted lines, and answers within each cage must add up to the sum shown in the top-left corner.
- Just like a number cannot repeat within a unit, no number may repeat within a cage.
Easy Killer Sudoku Strategies
Because Easy Killer Sudoku follows the same rules as regular Sudoku, you can use many of the same solving strategies you would for a normal puzzle. However, this type of Sudoku contains a twist — cage sums — which is why this variant is also known as Sumdoku.
The sum of all numbers in each cage is given in the corner, and this added constraint offers extra information you can apply to arithmetic-based strategies to solve the puzzle, including:
- Scan for one number at a time. Pick a single number and look for it across the puzzle, one row, column, and box at a time. Use standard Sudoku rules to eliminate cells where that number can't go. When a cell looks possible, quickly check its cage. If placing that number would make the cage sum impossible (too high/low) to complete, eliminate it. This often leaves only one valid cell for that number.
- Look for naked singles in units and cages. By focusing on these cells first, you add answers to the puzzle that may reveal additional placements.
- A one-cell cage with the sum of 1 (see bottom-middle block) must have the answer of 1.
- Cages with only one cell empty simply take a little subtraction to solve. If the cage sum in the top-middle block for two cells is 14 and one cell is already answered with 8, you can quickly see that 6 must be the answer in the remaining cell.
- Use the Sudoku solver for help. You can get step-by-step tips for solving by clicking the "Solver" button under the puzzle. If you get stuck or don't understand how best to move forward, the solver helps you understand the logic so you can place more answers in the puzzle.
Difficulty Levels
At first glance, Easy Killer Sudoku rules add more constraints and may appear to be more difficult than Classic Sudoku. But the cage sums actually add more information, giving you additional ways to strategize and solve, so you may find this even easier to solve because you can narrow down possible answers quickly. As your skills develop, you can move on to more challenging puzzles by advancing through other levels of difficulty, including:
