Logic Masters Deutschland e.V.

The solution code only depends on the main puzzle, Self Referential Critters, so feel free to skip the practice puzzles if you're feeling confident! Each bug uses an unconventional self-referential constraint, so they'll be introduced one-by-one via practice puzzles. The collection of puzzles is inspired by juggler's Full English Breakfast.

Practice 1: Ants. (Easy)

• 5x5 Sudoku rules: every row and column contains the digits from 1 to 5 exactly once each.
• Killer cage: the central cage contains the digits from 1 to 5 exactly once each.
• Ants are in ant-trails: in each row, the digit on an ant is the length of the longest ascending or descending sequence of consecutive digits containing the ant. For example, in the row "52341", the "3" or "1" could be an ant. (Ants don't have to be at the start of their ant-trails.)

Practice 2: Ants and Spiders. (Easy-Medium)

• Standard sudoku rules.
• Ants are in ant-trails (described above).
• Spiders catch smaller digits: the digit on a spider is the number of digits it is greater than in its web (i.e. cage). Digits in a web may repeat. For example, in a web with the digits {1,1,2,3}, the "2" and "3" could be spiders.

Practice 3: Ants and Crickets. (Medium)

• Standard sudoku rules.
• Ants are in ant-trails (described above).
• Crickets jump between big digits: the digit on a cricket is both the sum of the digits between the two largest digits in its row, and the sum of the digits between the two largest digits in its column. For example, if the column "451362" meets the row "645231" at the digit 4, the "4" might be a cricket.

The main puzzle: Self Referential Critters. (Hard)

• Standard sudoku rules.
• Ants are in ant-trails.
• Spiders catch smaller digits.
• Crickets jump between big digits.

(Full rules can be read in one block at the sudokupad link.)