One player (the Gamemaster) invents a rule that can be applied to yes-or-no questions. The other players try to guess the rule by asking yes-or-no questions. The Gamemaster answers the questions with "yes" or "no", not according to whether the questions are true, but according to whether they fit the rule.
Number of Players: 2 or more
Equipment: No equipment needed
Object: To guess the Gamemaster's rule and become the next Gamemaster.
One player is selected as Gamemaster. He devises a rule with which to answer questions, such as "The question must contain the letter 'E'." (See the Hints section for more sample questions.)
When the Gamemaster announces he has a rule, the other players take turns guessing the rule by asking yes-or-no questions. The Gamemaster answers according to the form of the question, not the content. For example, if the rule is that the question must be five words long or shorter, then the question "Was George Washington the first president of the United States of America?" will be answered "no", even though he was, while "Is George Washington president now?" will be answered "yes", even though he isn't.
Marty is Gamemaster. Ron is the only other player.
Marty: Okay, I have a rule.
Ron: Okay. Do you have skin?
Marty: No.
Ron: Do you have teeth?
Marty: No.
Ron: Do I have teeth?
Marty: No.
Ron: Did you go out today?
Marty: No.
Ron: Are you happy?
Marty: No.
Ron: Are you sad?
Marty: No.
Ron: Do the dogs need to go out?
Marty: No.
Ron: Is there still time?
Marty: No.
Ron: Is this bag yellow?
Marty: No.
Ron: Are you?
Marty: No.
[Time passes.]
Ron: Give me a clue! I haven't had a single "yes" answer!
Marty: All but one of the questions you asked have something in common. If you can figure out what it is, you'll have your clue.
Ron: Did you eat dinner?
Marty: No. But that's the second question that doesn't fit the pattern.
Ron: Will you go out today?
Marty: Yes.
Ron: My guess is that the question must be in the future tense.
Marty: That's right!
Kolodny's Game was invented by David Greene Kolodny and apparently was first described in the book Games for the Superintelligent by James Fixx. (Although Peter Suber mentions an "unnamed childhood game" with the same rules, which he decides to call "Noyes", in [1].)
This rules writeup: Ron_Hale-Evans? with Marty_Hale-Evans?