Involuntary Intoxication as an Affirmative Defense in Texas

In criminal law, proving intent is crucial, especially in specific intent crimes where it’s not just about the action but also about the intention behind it. But what happens if someone’s mental state is changed without their choice, such as by being drugged or forced to drink? This is where the defense against involuntary intoxication becomes important.

What Is An Affirmative Defense?

An affirmative defense is a legal strategy that allows a defendant to avoid or lessen liability for a criminal offense. While using an affirmative defense, the defendant acknowledges committing the act but presents a justification or excuse for their actions. This defense can help reduce the legal consequences of the offense. Examples of affirmative defenses include mistake of fact, mistake of the law, insanity, duress, entrapment, age, and intoxication.

Exploring the Definition of Intoxication

To determine if intoxication can be a defense to a crime in Texas, it’s important to understand how Texas defines “intoxication” for this purpose.

In Texas, the intoxication defense hinges on the impairment of mental or physical abilities resulting from ingesting a substance, as defined in Penal Code § 8.04 (b). Specifically, Texas Penal Code §49.01(2) outlines the criteria for intoxication, stating that a person is considered intoxicated if they lack normal control over their faculties due to consuming:

  • Alcohol
  • A controlled substance
  • A drug
  • A dangerous drug
  • A combination of two or more of the above
  • Any other intoxicating substance

Two Types of Intoxication

The use of the intoxication defense is quite restricted and usually hinges on whether the intoxication was voluntary or involuntary, as well as the level of intent needed for the criminal charge.

Voluntary Intoxication

It’s important to know that in Texas, claiming “voluntary” intoxication as a defense is not allowed. This means that if you choose to drink alcohol or use drugs and then commit a crime, you can’t use being intoxicated as an excuse under Texas Penal Code § 8.04(a).

However, Texas courts do recognize involuntary intoxication as a valid defense under specific circumstances. This occurs when:

  • The person had no choice or control over taking the intoxicating substance.
  • Due to being intoxicated, the person didn’t know that their actions were wrong.

This means that if you willingly took medication, even if you didn’t intend to get intoxicated, the court is likely to decide that you can’t use involuntary intoxication as a defense. So, what exactly is involuntary intoxication?

Involuntary Intoxication

In some cases, an individual may become involuntarily intoxicated, meaning they did not choose to ingest the intoxicant. Involuntary intoxication can be a defense if the person had no control over taking the substance and, due to severe mental impairment from intoxication, did not understand that their actions were wrong or could not conform to the law.

There are three primary scenarios where involuntary intoxication might apply:

  • The person was unaware that they were ingesting the intoxicant.
  • Force or duress was used to make them ingest it.
  • The intoxication resulted from a prescription drug.

However, involuntary intoxication due to prescription medication only applies if the individual is unaware of the drug’s potential intoxicating effects, as taking the drug for medical reasons involves a deliberate decision, not an attempt to become intoxicated.

It’s important to note that involuntary intoxication is a defense that challenges the mental state required for an offense. Therefore, offenses like driving while intoxicated, which do not necessitate a specific mental state, are unlikely to succeed with an involuntary intoxication defense.

Related Defenses for Involuntary Intoxication

There are three defenses related to a defendant’s intoxication, including:


Involuntary intoxication falls under the legal defense of unconsciousness. Like involuntary intoxication, unconsciousness provides a full defense to criminal charges.

It’s important to note that you can be considered legally “unconscious” even if you are physically able to move. This defense also applies if you are unconscious while sleepwalking, experiencing a blackout, or having an epileptic seizure.

Mistake of Fact

A mistake of fact means you’re not guilty of a crime if you reasonably misunderstood key facts, leading to no intent to commit a crime.

The mistake-of-fact defense is closely related to involuntary intoxication. Usually, your mistake must be reasonable for this defense to apply. But if you were involuntarily intoxicated, even an unreasonable mistake can be a valid defense.


The insanity defense is valid if you were legally insane when you committed a crime. Being “legally insane” means you have a mental illness or defect that either:

  • Makes you not understand your criminal act, or
  • Prevents you from knowing right from wrong.

It’s important to note that intoxication is different from insanity. Just being under the influence of drugs or alcohol doesn’t mean you’re legally insane.

Additionally, addiction to drugs or alcohol doesn’t count as legal insanity. This applies even if you have brain damage or a permanent mental illness from past drug or alcohol use.

Arrested? Don’t Plea, Call Me!

If you or someone you know is facing criminal charges and believes an involuntary intoxication defense may apply, it’s crucial to seek legal advice immediately. The Texas Criminal Defense Group can review the details of the case and determine the best course of action. Don’t wait until it’s too late—contact us today to schedule a consultation and protect your rights.