(US, law) An exception to the general rule of contract law that acceptance of an offer takes place when communicated. Instead, acceptance takes effect when a letter enters the postal system.

An observation that, in a parliamentary election, the ration of seats won by each party is proportional to the cube of the percentage of the vote obtained by each party

Synonym of first past the post

(logic, proof theory) A rule for combining (or modifying) well-formed formulas of a formal language in a truth-preserving manner (to yield new well-formed formulas).

(law) A notion of what should "count" as law.

(photography, film, visual arts) A normative rule that an image should be mentally or representationally divided in three horizontally and diagonally, and that the focus of the image should not be in the center of the resulting shape.

A doctrine in antitrust law which applies to contracts which "unreasonably" inhibit trade.

(Internet slang, fandom slang, informal) The proposition that it is possible to find genderswapped versions of every fictional character, especially as fan art on the internet.

(sports) A rule requiring that a player receive medical attention before continuing to play if he is bleeding or there is blood on him or his clothes.

(religion, Wicca) A religious tenet held by some Wiccans, stating that whatever energy, positive or negative, a person puts into the world will be returned threefold.