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 Nevada, voluntary intoxication is generally not a defense to criminal charges. The state's legal system operates under the principle that individuals are responsible for their actions when they voluntarily consume drugs or alcohol. However, involuntary intoxication can be a defense if it can be shown that the defendant was incapable of understanding the nature and quality of the act or that it was wrong due to the intoxication. This might occur if someone was drugged without their knowledge. As for voluntary intoxication, Nevada law does allow for it to be considered when specific intent is an element of the crime. This means that if a defendant was so intoxicated that they could not form the specific intent required for a particular crime, such as attempted murder, this may be a defense. However, whether the intoxication level was sufficient to prevent the formation of specific intent is a question of fact for the jury to determine. The relevant statutes and case law would be found in Nevada's penal code and interpreted through court decisions.