New to Killer Sudoku? Easy mode uses small cages with only one or two possible digit combinations - The perfect way to learn cage arithmetic without getting overwhelmed.
Every row, column, and 3x3 box sums to 45. If all cages in a row are known except one cell, the missing value = 45 - (sum of all other cage totals in that row). This is the single most powerful Killer technique.
Easy tip -
Start every puzzle by scanning for forced cages (sums of 3, 4, 16 or 17 in 2 cells). These give you free digits immediately. Then apply the 45 rule to any row or column where only one cage cell is unknown.
Frequently Asked Questions
Can digits repeat in a cage?
No - Every cage follows the no-repeat rule. Each digit appears at most once within any single cage.
What is the 45 rule?
Every row, column, and 3x3 box contains digits 1-9, summing to 45. Subtracting known cage sums within any unit reveals leftover cell values.
Is Killer Sudoku harder than Classic?
Generally yes - There are no given digits, so you rely entirely on cage arithmetic and elimination. Easy Killer is roughly equivalent to Medium Classic.