Intoxication (Voluntary)

The Law Commission's official report to Parliament, Intoxication and Criminal Liability (Law Com No 314), sets out the governing rule: voluntary intoxication prevents proof of criminal liability only if the subjective fault required by the definition of the offence is of a particular type — one of the culpable states of mind the courts label (confusingly) a 'specific intent'. The report gives murder as the paradigm example, where the fault element is the intent to kill or cause grievous bodily harm; if intoxication genuinely prevented the defendant forming that intent, the prosecution cannot prove the offence.

For 'basic intent' offences — those that can be satisfied by recklessness rather than requiring specific intent — voluntary intoxication provides no defence at all. The report explains that it follows from this analysis that D is never able to rely on his or her state of voluntary intoxication if D's argument as to its relevance is simply that it caused D's inhibitions to be reduced or D's moral vision to be blurred; the courts do not treat that kind of general disinhibition as relevant to liability, however genuinely intoxicated the defendant was.

The same principle carries through into partial defences to murder. CPS legal guidance on homicide confirms that self-induced intoxication is to be disregarded for the purposes of the loss of control defence, and that voluntary acute intoxication cannot found diminished responsibility, reflecting the same underlying policy that a defendant cannot rely on the effects of their own voluntary drinking or drug-taking to reduce their culpability for basic-intent or partial-defence purposes.