(law) A judge-made rule that overprotects a constitutional right in order to safeguard that right or facilitate detection of violations of it.

A long, straight-edged rule used by bricklayers for keeping their work even.

(cellular automata) An elementary cellular automaton based on the exclusive-or function.

(cellular automata) A one-dimensional binary cellular automaton rule, notable for solving the majority problem as well as for its ability to simultaneously describe several, seemingly quite different, particle systems.

(cellular automata) A one-dimensional binary cellular automaton rule displaying aperiodic, chaotic behaviour.

(law) The common-law rule according to which the unexpected frailty of an injured person is not a valid defense to the seriousness of any injury caused to them.

(law) A common law rule according to which police officers, firefighters, and other professional rescuers cannot collect on damages that occur in the course of their duties even in cases of clear negligence by other parties.

(law) A common law rule that establishes three age brackets for determining a juvenile's culpability for a tort or a crime.

(US, law) A common law rule according to which a baseball team cannot be held liable for injuries suffered by a spectator struck by a foul ball so long as the team has offered some protected seating.

(law) A common law rule according to which an ambiguous criminal law should be interpreted in the way most favorable to the defendant.