Untouchable 11: Master Challenge


by Carl Hoff

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The goal of this puzzle is to put 11 hexominoes within the board so that no two of them touch each other even at a corner. You can rotate the hexominoes (clicking them) and/or flip them over (press SPACE bar and clicking them). But you cannot overlap them. Note that each hexomino must be placed fully within the board.

Puzzle Background

Carl Hoff says: "Back in late 2008 and early 2009, I toyed with writing a program to solve the original Untouchable 11 puzzle made for Smart-Kit by Peter Grabarchuk. The hardest version of that puzzle has only 7 solutions not counting rotations or reflections. When I was invited to G4G10 and informed I needed a gift for the Gift Exchange, I immediately wondered if I could use that program to make an even harder puzzle based on the same rules. I felt Untouchable 11 was the hardest 11 piece 2D puzzle I was aware of at the time. Iíve now searched 100ís of 11 piece subsets of the hexominoes and to date this is the hardest set Iíve found which can still be placed on the 12x12 board. It has 2 solutions. The search continues for a set with just a single solution..."

Last Updated: April 5, 2012
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Untouchable 11
Play original Untouchable 11 puzzle on Smart-Kit.
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