Royal Sudoku - Version 1.0 Royal Sudoku is complicated version of sudoku game destined for real puzzle kings. Game is based on Japan puzzler also known as Suduko, Sudoko, Su do ku, Sodoku, Suduku. In it you must to compare numbers on game board to make them according the rules. Lets repeat history of this puzzle. The game refers to a number placement puzzle also known as Number Place in USA. First Japanese title of this puzzle was "Suuji wa dokushin ni kagiru". It's means that number is limited only single (unmarried). But this title is too long, then it was abbreviated as "Sudoku". So "SU" means number, "DOKU" means single. It seems to have first been published in the USA before being noticed and then popularised in Japan. And has the following simple rules. Each row, column and subgrid inibox comprises the numbers 1 through 16 or letters A through P or anything else. The attraction of the puzzle is that the completion rules are so simple and yet the overall task can be difficult. Sudoku is recommended by some teachers as an exercise in logical reasoning.