This puzzle was originally intended for the May 2021 monthly puzzle prompt in the CtC fan discord server. However, I didn't get it finished in time so I found a way to fit the theme of the June puzzle prompt instead.
The theme for the May puzzle prompt was Fairy Chess. Most chess sudoku puzzles have either an anti-knight or anti-king constraint which means that digits cannot be placed so that the same number is never placed a knight or king's move away from another square containing the same value. I have solved quite a few puzzles with these constraints. They can be great fun, but whenever I have tried to set a puzzle using these rules, I have found it very difficult to handle the global nature, especially of the knights move constraint.
I wanted to do a puzzle with crypto-clues spelling out the words FAIRY CHESS, and I struggled for a while, trying to come up with something that used an anti-camel or anti-giraffe constraint, but after a while decided to give up the idea.
Just over a week before the end of the month I had the idea of using a positive, instead of a negative constraint. So, instead of digits being prevented from being a chess move apart, I could make it so that certain numbers must be a chess move apart. I found this idea much easier to work with. Unfortunately, I didn't quite get it finished and properly tested in time for the end of May. For the June prompt, people were encouraged to dedicate a new puzzle to a particular person. Most people obviously dedicated puzzle to people that had particularly inspired them, close family members, etc. I thought it might be fun to dedicate this puzzle to myself, and to refer to myself as the late Phil Preen. Anyway, here is the resulting puzzle. I hope you enjoy it:
Sandwiches at the Fairy Chess Park
This puzzle is dedicated to the late Phil Preen.
I am not dead, but I am late with this puzzle because it was supposed to be for last month's prompt and I didn't finish it in time. I have also added some extra unnecessary clues as red herrings so that it can be late for the April prompt too.
1=🐫(1,3) 6=🦒(1,4) 9=🐘(2,2) 4=3🤗
• Normal sudoku rules
Each row, column & 3x3 box contains the digits 1-9
• Normal sandwich rules
The clues outside the grid indicate the sum of all the digits between the 1&9 in that row or column. If the value is preceded by a < symbol, the sum is less than the specified value.
• Crypto Clues
Digits in some of the clues have been replaced with letters. Each letter represents the same digit wherever it appears. Each different letter represents a different digit.
• 1s are Camels 🐫 (1,3)
Each 1 in the grid is a camel move away from at least one other 1. A camel moves like a chess knight except that instead of moving 1 square in one direction and 2 squares in another, it moves 1 square in one direction and 3 squares in another.
• 6s are Giraffes 🦒(1,4)
Each 6 in the grid is a giraffe move away from at least one other 6. A giraffe moves like a chess knight except that instead of moving 1 square in one direction and 2 squares in another, it moves 1 square in one direction and 4 squares in another.
• 9s are Elephants 🐘(2,2)
Each 9 in the grid is an elephant move away from at least one other 9. An elephant moves like a chess knight except that instead of moving 1 square in one direction and 2 squares in another, it moves 2 squares in one direction and also 2 squares in another.
• 4s are Threehuggers
Each 4 in the grid is no more than 1 square away from a 3 (vertically, horizontally or diagonally).
