What is a puzzle? A very dry definition from 1984 (Chris) is: rule-based systems, like games, but the goal is to find a solution, not to beat an opponent. Unlike games, puzzles have little replay value. Problematically, part of the definition uses the word games, which is a whole other Gordian knot to be dealt with elsewhere. My personal favorite definition, from Isaacs, however, is far simpler: A puzzle has two features,
It is fun
It has a correct answer
On the face of it, this is.. a GREAT definition. It makes some basic assumptions that you have a gestalt in your head already of what a puzzle is, but since that’s a fair thing to assume, it cuts right to the quick. In contrast to a game, a puzzle has a correct answer. My favorite example of this point is the “game” Tic-Tac-Toe.
Tic-Tac-Toe is not actually a game. It has rules like a game, it has structure, like a game. You even aim to beat an opponent, like in a game (I’ll note that the opponent in a game does not need be another person). But.. Tic-Tac-Toe has a correct answer. If you play Tic-Tac-Toe enough times, you’ll either figure out, or remember having figured out previously, the correct combinations that will guarantee victory. If you’re the start player, you’ll either win or draw, every time, once you figure out the handful of possible sequences that can occur. You did it! You didn’t just beat your opponent, you beat the whole game. You solved it. Can what you’re doing be considered to be playing anymore (again, play is a word that I’ll lean on the gestalt of for the meaning)?
Lots of “games” aren’t really games. Some of them are not games for other reasons (most notably a general lack of meaningful decision making), but any game that is solvable is only a game until you solve the puzzle that it actually is. And as Chris put it, “puzzles have very little replay value”.