1) Rules

• Sufficiently well-defined that players do not argue about them and/or they are implementable on a computer.

• A rule relates only to specified parts of the game and game context. (Decontextualization.)

• In non-electronic games, rules become unambiguous over time because players find it annoying to argue about them.

• Compare two rules:

• Check mate is when the king is in a hopeless position.

• Check mate is when the king is checked [can be captured in the next move] and the threatened player is unable to bring the king into an unchecked position in one move.