I kept myself busy over the Christmas break (when I wasn’t feeding the birds and entertaining my cat) by adding 13 new Interactive Puzzle pages to this website. The puzzles work in modern web browsers (Chrome, Firefox, Safari, IE 9 or later), on iPads, and on some Android tablets . I think these puzzles are […]

Whit McMahon, a puzzle constructor, wrote to me recently to share a new kind of puzzle he created last year called Balance Quest®. In these numeric logic puzzles, you fill in blanks so that the sum of each box is made by adding the numbers in the adjoining half-height boxes. Note that some of these […]

While grocery shopping this evening, I happened to notice a box of Kraft Mac & Cheese that was turned around, with a familiar looking maze on the back. While this maze may look generic to you, it looks quite recognizable to me, because I spent quite a bit of time writing software that produces mazes […]

I occasionally get requests to add new puzzle varieties to the collection. I have to ignore a lot of these, because there are 24 hours in a day. However, the last request I received, for Masyu puzzles, was hard to ignore, since I’ve enjoyed solving these myself for the past few years, and I’d love […]

Roderick Kimball wrote to tell me about an interesting logic puzzle he’s developed called Path Puzzles. In these puzzles, you must make a path that winds its way from one opening to another on the edge of the grid. The clue numbers tell you how many squares in each row or column are occupied by […]

John Welch writes an excellent blog for advanced Sudoku Solvers called Systematic Sudoku. Every Tuesday he posts a new detailed analysis of a tough puzzle, one of his goals being to understand the comparative difficulties of various sudoku publications. Sudoku difficulty is hard to measure and describe, and different publications (including this website) use different […]

I recently added a new puzzle variety to Krazydad, called Jigsaw Sudokus. These are very similar to normal Sudokus. Like those puzzles, each row and column contain all the digits 1 through 9. However, these puzzles are missing the 3×3 blocks found in regular Sudoku. Instead, the puzzles are divided into a set of irregular […]

Lately, I’ve been solving Krazydad puzzles on an iPad, using my finger, or a stylus, rather than printing them out and solving with a pencil. My iPad app of choice for printable puzzles is UPAD, a great little drawing app that works well with PDF files. It is available in both free and paid versions. […]

David Millar, of the excellent puzzle site The Griddle, has launched a new collaborative puzzle site called Perplexible. The intent is to provide a forum for diverse puzzle authors to post new creations. I’ve posted an unusual Slitherlink there, and hope to post more unique puzzles, in the future. I occasionally get emails from puzzle […]