The Krazydad Discord server is a new place where you can talk to me, and meet other people who are interested in puzzles. You can report problems or mistakes with this website, suggest new features or new puzzles, get periodic announcements from me, or discuss the theory-of-puzzles and other deep thoughts. Maybe I'll see you there!
Interactive Puzzles by Krazydad
Solve in your web-browser, or on an iPad, Kindle Fire or Android tablet.
Oh my gosh, they're full of stars! A fun object-placement puzzle currently published in The New York Times as Two Not Touch.
Sometimes called Tectonics or Number Blocks, these puzzles have very simple rules but can be extremely challenging!
An addictive binary puzzle, also known as Binairo, Binoxxo, Tic-Tac-Logic, Takuzo, Bineiro, Brain Snacks, Unruly, Zinero and Zernero.
Protect aliens from mutant cactus in this engaging hybrid of Slitherlink, Masyu, and Cow & Cactus.
A solitaire version of the classic strategy game in which you hunt and sink a hidden enemy fleet.
Also known as Hashiwokakero, connect islands to form a network of bridges in this spatial-reasoning puzzle.
Conjoined Sudoku grids make for a longer-lasting and most satisfying solving experience.
Jigoku means hell in Japanese, and these fiendishly difficult Sudoku puzzles with greater- and less-than signs will show you why.