This is an ongoing project to collect rules for interesting games that can be
explained in no more than 100 words, and which (mostly) require no more than
a deck of cards, six dice and a pen and paper. Any ambiguities can be rehydrated through common sense (eg. if a game uses
points but specifies no winner, the most points win).
The Thinker thinks of a person and says the first letter of their surname. Others take turns to ask a yes/no question where the asker has a person in mind for "yes" (who fits all confirmed information about the mystery person); the Thinker either says "No, I am not [name]", naming someone who fits but is not the mystery person, or concedes. If conceding, the asker reveals who they had in mind and may ask direct yes/no questions to the Thinker until they answer "no" to one. A guesser wins if they mention the Thinker's chosen person on their turn.
The Server thinks of an object. Another player makes a guess as to what this object might be, and this automatically becomes the best guess so far. Other players then make guesses. For each guess: if it is closer than the current best guess, the Server announces that this is the new best guess; otherwise, the Server declines it but names something that the guess has in common with the object. (eg. "A wasp?" "No, a calculator is still the best guess, but like a wasp, my object has a sharp point.") A correct guess wins.
Both players think of their own four word key sentence. Each turn, a player announces a "test sentence", and their opponent indicates whether each word in their own key sentence is alphabetically before ("up") or after ("down") the corresponding word in the test. (For example, if a player's key sentence was "HAVE A NICE DAY" and the other tested with "LET THERE BE LIGHT", the player would answer "up, up, down, up".) Repeat until a sentence is guessed. To shorten the game, announce when a word has reached the correct initial letter.
Each player secretly notes down a five-letter word. Players take turns to call out five-letter words, their opponent responding by saying how many times the called word's letters appear in their secret word (eg. a call of WORLD against a secret word of HELLO results in "3"). If the called word is the secret word, the caller wins. Players may note down an alphabet and cross out letters as they are eliminated, for reference.
by Morton M. Rosenfeld
One player chooses a secret rule that any given sentence may or may not fit (eg. "ends with a vowel"). Other players ask yes/no questions, which the rule chooser answers with "yes" if the question sentence fits the rule and "no" if it does not. The first player to guess the rule wins.
by David Greene Kolodny
No More Jockeys
Players take turns to name a person and then exclude a category that the person belongs to, eg. "Buster Keaton: No more actors." Categories can be qualities of the person, or of their name. Once a category is excluded, people it covers cannot be named. A player is eliminated if (1) they can't think of a person, (2) another player correctly challenges them for a move that breaks earlier exclusions, (3) they issue three failed challenges, (4) someone asks them to "name another" who also fits their created category, and they are unable to.