Well, this is not board or card game, but it has same purpose. Combination/logic puzzles like Sudoku, Mastermind, etc. should be on-topic?
In Programmers.SE we embrace some related proposals to avoid too narrow sites.
Is there any real valid reason to Rubik's Cube be off-topic? Can we be inclusive before the SOIS team tell us to be so?
Rubik's cube is exactly the examplar case that gives me trouble. I think emotionally we feel the cube is a puzzle. But it's hard for me to deny that 'produce a cube with solid-coloured faces' is a victory condition for a one-player game, and there are a clear set of legal moves to use to achieve it. (That there is a known algorithm for achieving it is clearly not an obstacle; there's a known solution to Connect 4 as well but it's clearly a game.)
Pace gomad's answer, I think single-player games and puzzles usually both possess a defined winning condition (a goal), and a legal sequence of moves to attempt to achieve it.
Proposal: A single-player activity with a goal and legal moves is a game, as opposed to a puzzle, if it also possesses a clear losing condition; that is, a game-state under which the goal can no longer be achieved.
This rules out Rubik's cube, crosswords, and other puzzles where you can always keep trying. It allows Freecell and other solitaire card games (they usually have a can't-try-any-more-moves end-state). And importantly for my peace of mind, will always allow solitaire games such as, say, solitaire Pandemic or Death Angel, which we clearly do wish to be on topic!
The Rubik's cube is an interesting case. I would generally classify it as a puzzle, rather than a game.
However, we generally consider solitaire variations of games to be on topic, and might consider solitaire only games (like Klondike or Freecell) to be on topic. I'm not sure how you could draw a line between solitaire and a Rubik's cube in any meaningful way.
I have tried to provide some criteria for distinguishing puzzles from games in my answer to another question; the one I offered is that if it has a dynamic or random setup, or random events during the game, then it could be considered a solitaire game, while if it's static unless someone or a computer creates a new instance (like a crossword or sudoku), then it's a puzzle and off topic. But by this definition, solving a Rubik's cube would be on topic.
So, I'm wondering if anyone has any better way of distinguishing a solitaire game from a puzzle, or if we just want to say that solitaire games are off-topic, or that puzzles are on-topic.
No.
I think there is a difference between puzzles and boardgames. I'll admit that there is some overlap, but I do not believe that we should expand to encompass every puzzle activity.
Update, so far we've had 1 topic on Rubik's Cube and it has been closed by the communityRobert Cartaino.
I wouldn't mind if puzzles are included. But I can imagine that they don't fit the general concept of the site.
But then again, you can see a puzzle as a one person game.
A Rubik's Cube, like many puzzles, is a toy, not a game. A toy is something you can play with, but it has no ruleset. A game is a rule set that defines an action framework. Actions within that framework constitute playing the game.
If there was some game - a ruleset defining a framework of actions - involving Rubik's Cube, then that would be on topic. The cube itself is not.
