A
prophylactic rule is a judicially crafted rule that overprotects a
constitutional right, and gives more protection than such right might abstractly seem to require on its face, in order to safeguard that constitutional right or improve detection of violations of that right. An example is the case of
Miranda v. Arizona which adopted a prophylactic rule (“
Miranda warnings") to protect the
Fifth Amendment right against self-incrimination. The
exclusionary rule, which restricts
admissibility of evidence in court, is also sometimes considered to be a prophylactic rule.