Is being drunk a defence?
Generally speaking, the law does not provide an exemption from criminal liability for a crime simply because you were intoxicated at the time. However, the state of intoxication may impair your intention to commit a crime and as such can give rise to a defence including duress, self-defence and sudden extraordinary emergency. 
This article focuses on offences committed on or after 1 November 2014. If you are alleged to have committed a criminal offence (other than murder) prior to this date, and intoxication may be relevant to your defence, the common law regarding intoxication will apply.
The impact of intoxication on your defence
The law defines that ‘intoxication’ is being under the influence of or intoxication due to alcohol, drugs or another substance.
Whilst being intoxicated itself is not a defence to a criminal charge, being intoxicated can impair your intention to commit a crime. Further, intoxication may impair your understanding of the circumstances, such as your perception of being under duress.
Some offences include a consideration of ‘reasonableness’ as one of the elements of a defence. In this circumstance, a reasonable person or a reasonable response will be a person who is not intoxicated. The law generally treats intoxication to be self-induced, unless you became intoxicated involuntarily (e.g. someone spiked your drink), due to fraud, duress or reasonable mistake or as a result of taking a prescription drug, medical cannabis or over-the-counter medication (provided it was taken in line with the prescription, authority or manufacturer recommendations). If your intoxication was not self-induced, reasonableness will be measured against your behaviour whilst intoxicated.
Impact on the elements of a charge
Intoxication can also be used to disprove one of the elements of the alleged offence, regardless of whether the alleged offence is prior to 1 November 2014 or after this date. The intention is very relevant to criminal cases and is a crucial element in most offences. Your level of intoxication at the time of the alleged offence can be a relevant consideration in whether you voluntarily committed the alleged act or formed the relevant intention to commit that act.
For example, if you are charged with intentionally causing serious injury, the level of intoxication can be used to disprove the element that you formed an intention to cause a serious injury.
The distinction is that the intoxication must have impaired your intention to commit a crime, rather than your capacity to form an intention to commit it. It is irrelevant whether you remember committing the offence or not.
Thus, your state of intoxication at the time it is alleged you committed a criminal offence may be relevant, as the elements of the specific offence may not be able to be proven beyond reasonable doubt. However, it is important to speak with a lawyer to assess the potential impact your intoxication may have on your case.
 Crimes Act 1958 (Vic) ss 322K, 322O, 322R.
 Crimes Act 1958 (Vic) s 322T(1).
 Viro v R (1978) 141 CLR 88
 DPP v Parker  VSCA 101 .
 Crimes Act 1958 (Vic) s 322T(2)(3).
 Crimes Act 1958 (Vic) s 322T(5).
 Crimes Act 1958 (Vic) s 322T(4).
 Crimes Act 1958 (Vic) s 16.
 R v O’Connor (1980) 146 CLR 64.
 R v O’Connor (1980) 146 CLR 64.
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Views expressed in this article are not necessarily endorsed by Leanne Warren and Associates.