DPP v Camplin (1978) was an English criminal law appeal to the House of Lords in 1978. Its unanimous judgment helped to define the main limits of defence of provocation chiefly until Parliament replaced the defence with one of "loss of control" in the Coroners and Justice Act 2009. Its ratio decidendi continues to have precedent value as the new "loss of control" defence is a renaming to avoid creep of the term into scenarios for which it was never intended, above all a blurring with diminished responsibility.