In the spring of 2020, when everyone was spending a lot more time indoors, my wife Mara and I were among many people who discovered the delightful Cracking the Cryptic channel on YouTube, where two puzzle enthusiasts (Simon and Mark) solve various types of puzzles, with a particular emphasis on Sudoku and its variants.

As well as providing entertainment and exercising our minds, I believe that solving Sudokus together helped Mara and me improve our communication and teamwork skills -- which has been especially helpful since we became parents in May 2021! It also inspired me to create some Sudoku puzzles of my own, starting in the spring and summer of 2023, which I am sharing below.

If you're reading this, it's likely that you're already familar with standard Sudoku rules (each of the digits 1 through 9 must appear exactly once in each row, each column, and each 3 by 3 box). In each of my puzzles, standard Sudoku rules apply, as well as additional rules which are briefly explained below.

If you want more explanation of the various types of additional rules (sandwiches, thermometers, arrows, killer cages, anti-knight constraints, etc), you can either read Dennis Chen's page or watch some of the videos at Cracking the Cryptic.

My puzzles are listed in the order in which I composed them. I am always open to advice or constructive criticism. Hope you enjoy!




Puzzle #1 is a Sandwich Thermo Sudoku. You can play it at f-puzzles.com or you can view it as an image for printing or downloading.

	 Clues outside the grid are "sandwich" clues: they give the sum of the digits that are "sandwiched" between the 1 and 9 in the clue's row or column.
	 In thermometers, digits must increase (not necessarily by 1) as we move from the bulb to the tip.

Puzzle #2 is a Killer Arrow Sudoku. You can play it at f-puzzles.com or you can view it as an image for printing or downloading.

	 Digits in a "killer cage" must sum to the number given in the top left corner of the cage.
	 Digits on an arrow must sum to the digit in that arrow's circle.

Puzzle #3 is a Killer Arrow Sudoku. You can play it at f-puzzles.com or you can view it as an image for printing or downloading.

	 Digits in a "killer cage" must sum to the number given in the top left corner of the cage.
	 Digits on an arrow must sum to the digit in that arrow's circle.

Puzzle #4 is an Arrow Sudoku. You can play it at f-puzzles.com or you can view it as an image for printing or downloading.

	 Digits on an arrow must sum to the digit in that arrow's circle.

Puzzle #5 is an Antiknight Killer Arrow Sudoku. You can play it at f-puzzles.com or you can view it as an image for printing or downloading.

	 Digits that are a knight's move apart (in chess) must be different.
	 Digits in a "killer cage" must sum to the number given in the top left corner of the cage.
	 Digits on an arrow must sum to the digit in that arrow's circle.

Puzzle #6 is a Thermo Sudoku. You can play it at f-puzzles.com or you can view it as an image for printing or downloading.

	 In thermometers, digits must increase (not necessarily by 1) as we move from the bulb to the tip.

Puzzle #7 is an XV (-) Sandwich Sudoku. You can play it at f-puzzles.com or you can view it as an image for printing or downloading.

	 Digits separated by an X must sum to 10. Digits separated by a V must sum to 5.
	 Negative constraint: Digits NOT separated by an X or V must NOT sum to 10 or 5.
	 Clues outside the grid are "sandwich" clues: they give the sum of the digits that are "sandwiched" between the 1 and 9 in the clue's row or column.