## Facts

- Mr. Allen consumed homemade wine provided by a friend, claiming to be unaware that it contained much more alcohol than normal.
- He subsequently committed unlawful acts while intoxicated.
- Allen's defense at trial was based on his mistaken belief regarding the wine’s alcohol strength.
- The trial court rejected Allen’s argument that his misunderstanding about the drink’s potency excused his conduct.

## Issues

1. Whether a defendant’s mistake about the alcohol content of a drink can render their intoxication involuntary for the purposes of criminal liability.
2. Whether such a mistake affects the defendant’s capacity to form the necessary mental element (mens rea) for criminal offenses, particularly distinguishing between basic and specific intent crimes.
3. Whether the rules set out in DPP v Majewski regarding voluntary intoxication and criminal responsibility apply to cases involving mistakes about drink strength.

## Decision

- The Court of Appeal found that an error about a drink’s alcohol strength does not make intoxication involuntary.
- The court distinguished between involuntary intoxication (where the defendant is unaware of consuming alcohol at all) and cases of mistaken strength, holding only the former may constitute a defense if it negates mens rea.
- The rules established in DPP v Majewski were affirmed: voluntary intoxication, including misjudged alcohol strength, generally cannot excuse liability for basic intent offenses.
- The decision clarified that only if the mistake genuinely prevents formation of specific intent required for a particular crime, it may be relevant, but each case must be assessed on its facts.

## Legal Principles

- Voluntary intoxication, even due to honest mistakes about alcohol strength, does not constitute involuntary intoxication.
- The defense of intoxication is only available if the defendant is unaware they are consuming an intoxicant and, as a result, lacks the required mens rea.
- DPP v Majewski remains authoritative: voluntary intoxication is not a defense to crimes of basic intent but may be relevant for specific intent crimes if the intoxication negates intent.
- The nature of the defendant’s error (about the presence vs the strength of alcohol) is central to assessing criminal responsibility.

## Conclusion

R v Allen [1988] Crim LR 698 clarified that a mistake regarding the strength of an alcoholic drink does not make intoxication involuntary and thus generally offers no defense to basic intent offenses, reaffirming the principles set out in DPP v Majewski while allowing limited exceptions for specific intent crimes where intent formation is genuinely impeded.
