Chapter 43: ABCD
You are given an empty grid together with clue numbers on the outside. Your goal is to fill every cell with a letter so that each row and column contains the required number of each letter, and matching letters never touch horizontally or vertically.
This documentation is based on Lennard Sprong’s unreleased puzzle contribution repository, x-sheep/puzzles-unreleased. The puzzle is also known as ABC-Kombi or ABCD-Ratsel.
More information: janko.at/Raetsel/Abc-Kombi
43.1 ABCD controls
ABCD uses the same control scheme as Solo, except that you enter letters instead of digits.
Left-click a cell and type a letter to enter it. Press Backspace or Space to clear a cell.
Right-click a cell and type a letter to add a pencil mark. Pencil marks are purely for your own notes.
You can also move the selection with the arrow keys. Press Enter to toggle between normal entry and pencil-mark entry.
Press M to fill every empty cell with all possible pencil marks.
43.2 ABCD parameters
These parameters are available from the Custom... option on the Type menu.
Width, Height: Size of the grid, excluding the outside clue area.
Letters: Number of distinct letters used in the puzzle.
Remove clues: Hides some outside counts to increase difficulty.
Allow diagonal touching: If disabled, identical letters may not touch diagonally either.
Status: fully implemented and playable in the unreleased collection.