Intoxication due to a defendant’s voluntary consumption of drugs or alcohol isn’t usually a defense to criminal charges—but if the intoxication was involuntary, it may be a defense on the basis that the defendant did not understand what he was doing or that what he was doing was wrong. And some states allow a defendant to assert a defense that his voluntary intoxication prevented him from forming the specific intent to commit the crime (attempted murder, for example). But this is a question of fact that the jury will usually determine.

The availability and definition of any defense to criminal charges based on the defendant’s voluntary or involuntary intoxication is usually located in a state’s statutes—often in the penal or criminal code.

In Virginia, voluntary intoxication is generally not a defense to criminal charges. The state does not allow voluntary intoxication as a defense to negate the general intent to commit a crime. However, there are limited circumstances where voluntary intoxication may be relevant to specific intent crimes, where the defendant must have had a particular state of mind to commit the offense. In such cases, evidence of intoxication may be considered to determine whether the defendant was capable of forming the specific intent required for the crime. In contrast, involuntary intoxication can be a defense if the defendant can prove that they were involuntarily intoxicated and, as a result, unable to understand the nature of their actions or to distinguish right from wrong. The specifics of these defenses and their applicability are detailed in Virginia's criminal statutes and case law, and the determination of whether an intoxication defense is valid is typically a question of fact for the jury to decide.