Samurai Sudoku

Einstein samurai sudoku

Fewer than 50 givens. Every puzzle is certified solvable through pure logic, no guessing or bifurcation required. These are the hardest samurai sudoku puzzles on this site.

At this level, the board looks mostly empty. Most individual grids have barely enough givens to get started. Your first placements almost always come from shared-box intersections where both parent grids combine to eliminate all but one candidate.

You need the full toolbox: naked and hidden singles, naked and hidden pairs and triples, pointing pairs, box/line reduction, and long cross-grid chains. Some puzzles require chains that touch all five grids before a single cell resolves.

Times vary widely. Fast solvers who are comfortable with advanced techniques might finish in 45 minutes. Others take well over an hour. If Challenge mode (no hints, no undo) at Einstein level sounds appealing, you're in the right place.

For more of the hardest puzzles across all types, see the hardest puzzles.