Spiral Grid

Spiral grids are a type of alternate grid shape for puzzles, in which cells follow a spiralling, linear path from out to in (or in to out). Crossword-like puzzles using these types of grids are somewhat popular, and allow for a unique style of cross-checking answers.

Puzzle Application
Spiral grids are almost exclusively found in word puzzles, particularly for clue-based puzzles. They provide a unique way of constructing a word puzzle, in that entries can only usually be entered linearly, one after another, with the spiral itself just acting as an aesthetic choice. What is commonly done, then, is to have two sets of clues, one corresponding with the words seen when reading out-to-in, and one corresponding with the words seen when reading in-to-out. This back-and-forth method can still be achieved with straight lines, but spirals still tend to be the go-to way of presenting them.

Spiral grids are not always made up of a single line, however, and may involve several parallel spirals, either acting separately and allowing for clues travelling perpendicular to the spiral, or allowing for an alternate path through the 'grid', like a zig-zag passing through multiple layers of the spiral at a time.

Examples

 * - The first spiral-based puzzle featured in the MIT Mystery Hunt, using a basic spiral and using as part of its extraction.
 * - A relatively vanilla spiral puzzle, using a common extraction for such puzzles.
 * - A unique take on the spiral crossword, both from a visual and functional perspective. It uses a loose spiral (only making just under one and a half rotations), and refuses to actually mark the spaces in which entries start or end in the puzzle. This requires a lot more logical deduction from solvers than normal.