Beginning solvers might still have difficulty with the "easy" GAS puzzles. We have been setting a series of puzzles for friends who are still just beginning to explore variants in sudoku. These pre-GAS puzzles we have chosen to call Brassica puzzles.

Cracking the Cryptic introduced the idea of "genuinely approachable sudoku" puzzles, known affectionately as GAS puzzles. These are puzzles that are designed to be at a level that most solvers have a hope of completing even if it takes a while to follow the logic or learn the variant rules.

In the same vein, post-GAS-difficulty puzzles we have chosen to call Indigestion puzzles. Some of the deductions, while logical, may cause brief heartburn, ranging from mild to severe. Each of these puzzles has an estimated difficulty based on reactions from solvers in the community.

Somewhat more intense than mild indigestion are the Heartburn puzzles, which may require more difficult deductions. Intended for more experienced solvers and those seeking a challenge, each of these puzzles has an estimated difficulty of at least 3.5/5 based on reactions from the solving community.