What Makes a Good Puzzle? One Answer, Fair Clues and an Aha Step
A good puzzle has one answer, fair clues, a clear goal and an aha step. What research on logic, weighing and dissection puzzles shows about each.
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Articles about unique solution
Puzzle With a Unique Solution: How Designers Make Sure
A good puzzle has exactly one answer. How designers and researchers check every possibility so a puzzle ends with a single solution.