The Times Samurai Su Doku 3Paperback, 1 December 2014

For anyone who loves the challenge of su doku but manages to solve them within minutes--samurai su doku

With its larger and more complex grid, samurai is su doku multiplied. It is a five grid interlinked version and, as with traditional su doku puzzles, every column, row, and three by three box contains the digits 1 to 9. Where the puzzles overlap, the rows and columns do not go beyond their usual nine by nine length but the interlocking boxes provide more clues--and more complexity. With 100 samurai su duko at four levels--30 Mild, 30 Difficult, 30 Super Difficult, and 10 Deadly--even the speediest of solvers will be agonizing over this collection of ultra-complex, extended brain-teasers.