World Sudoku Championship
- 1st WSC: Lucca, Italy, 2005
- 2nd WSC: Prague, Czech Republic, 2006
- 3rd WSC: Goa, India, 2007
- 4th WSC: Zilina, Slovakia, 2008
- 5th WSC: Phildelphia, USA, 2009
These guidelines were in part inspired by Thomas Snyder's [Open Letter to the World Puzzle Federation Regarding Sudoku Championships]. The first draft was written by Wei-Hwa Huang.
- 30% to 70% of the puzzles in the championship (ideally 40%) should be "classic" Sudoku.
- With regards to Sudoku Solving Strategies: Puzzles for which bifurcation solving techniques excel over heuristic solving techniques should be minimized, eliminated, or labeled. They should not be used during playoffs.
- Sudoku Variants that reward solving heuristics that are significantly different from classic Sudoku should be minimized, eliminated, or labeled.
- The standards of competition should be publicly available to all contestants. References to "secret variants" are entertaining but should be avoided at all costs.
- The bonus and tiebreaker rules should be structured so that it is never beneficial to deliberately not solve a puzzle.
- The bonus rules should be structured so that it should be extremely unlikely for bonus points to dominate puzzle-solving points, and very unlikely for bonus points to be completely irrelevant. Organizers should not assume that they can predict how fast or how slow competitors will be.
- Puzzles that are "closer" to a solution should get more partial credit, particularly in a playoff or other situation in which a "tie" must be broken.