#The hardest maze pages free#

Identified in the same way as the Killer Sudoku presented in this article, the hardest Calcudoku was a 9×9 puzzle published on April 2, 2013, which only 9.6% of the regular puzzlers at managed to solve. Calcudoku was invented by Japanese math teacher Tetsuya Miyamoto, who called it 'Kashikoku naru' ('smartness'). The Hardest Calcudoku PuzzleĪ Calcudoku is similar to a Killer Sudoku, except that (1) any operation can be used to compute the result of a 'cage' (not only addition), (2) the puzzle can be any square size, and (3) the Sudoku rule of requiring the numbers 1.9 in each 3×3 set of cells does not apply. For example, the first problem on this page has as a solution: all patterns on the left are triangles. The 6 patterns on the right do not conform to this rule. To solve the above puzzle, published on Harry Foundalis' website, you have to find a rule that the 6 patterns on the left hand side conform to. They became more widely known after Douglas Hofstadter, an American professor of cognitive science, mentioned them in his book 'Gödel, Escher, Bach'. This type of puzzle first appeared in a book by Russian computer scientist Mikhail Moiseevich Bongard in 1967. Easily the hardest was the Killer Sudoku shown above, published on the 9th of November 2012. From a large number of highest rated puzzles at, I measured what percentage of puzzlers solved them on the day they were published. The World's Hardest Killer SudokuĪ Killer Sudoku is very similar to a Sudoku, except that the clues are given as groups of cells + the sum of the numbers in those cells.

You can read about making this puzzle even harder on the Physics arXiv Blog. The original article can be downloaded here. Boolos called it 'The Hardest Logic Puzzle Ever'. You do not know which word means which.Īmerican philosopher and logician George Boolos described the above riddle which was devised by Raymond Smullyan and published it in the Harvard Review of Philosophy in 1996. The gods understand English, but will answer all questions in their own language, in which the words for yes and no are da and ja, in some order.

Your task is to determine the identities of A, B, and C by asking three yes-no questions each question must be put to exactly one god. True always speaks truly, False always speaks falsely, but whether Random speaks truly or falsely is a completely random matter. The Hardest Logic Puzzle Ever Three gods A, B, and C are called, in no particular order, True, False, and Random. More information on how Inkala's puzzles are rated is on his website. In 2012, Finnish mathematician Arto Inkala claimed to have created the 'World's Hardest Sudoku'.Īccording to the British newspaper The Telegraph, on the difficulty scale by which most Sudoku grids are graded, with one star signifying the simplest and five stars the hardest, the above puzzle would 'score an eleven'. Sudoku is easily the most played and most analyzed puzzle in the world, so coming up with the hardest one is no mean feat. All of them, however, are promised to test your solving skills to the absolute limit and keep you busy for hours, if not days.įind an even harder puzzle? Be sure to let me know! For more information about this project and other logic puzzles visit my website 1. Some of these puzzles can be solved right on this page while others can be downloaded or reached elsewhere. In the following list you will find both familiar puzzles and games such as Sudoku and Calcudoku as well as lesser known ones such as the Bongard Problem and Fill-a-Pix. Every once in a while I added a new type of puzzle, until I ended up with a list of 10. After having created number puzzles like Calcudoku and Killer Sudoku for many years, I decided to try and find the most challenging ones out there. So you think you are clever, right? Then here is your chance to pit your brain against some of the world's hardest logic puzzles ever created.

#The hardest maze pages free#

Play our free puzzles online or try them out on your iPhone or iPad!