Consent as a Defense

Fundamentals of Criminal Law by Adam J. McKee

Consent by the victim can also form the basis of a justification defense to criminal conduct.  Consent is most commonly used as a defense to sex crimes such as rape, and lack of consent is a criminal element of most sexual offenses that must be proven beyond a reasonable doubt.  

Consent by the victim can operate as a justification defense against allegations of criminal behavior. It often arises in cases related to sex crimes, such as rape, where the absence of consent forms a fundamental element of the crime that must be established beyond a reasonable doubt.

Consent in Physical Harms and Contact Sports

In scenarios involving physical injuries during contact sports, such as boxing and football, there’s an implicit understanding that players have consented to potential harm inflicted upon them. However, the principle of consent is typically not extended to situations where grave bodily harm or death is anticipated. Furthermore, in cases where the defendant’s approval or acceptance is essential for the charge, such as trespassing, which mandates unauthorized presence on a property, demonstrating consent can nullify the prosecution’s case.

Requirements for Valid Consent

Consent can only be recognized as a defense if it is given knowingly and willingly by the victim. The Model Penal Code stipulates that consent is ineffective if rendered by someone legally unfit to authorize the conduct or if the individual is evidently unable to make a reasoned decision due to age, mental conditions, or intoxication. Moreover, consent must be rooted in the victim’s full comprehension of the act’s nature and its potential repercussions. For instance, statutory rape charges dismiss the defense of consent as it is posited that young individuals cannot grasp the gravity and possible outcomes of sexual activities.

Voluntariness of Consent

The principle of voluntariness is paramount when considering consent as a defense in legal cases. At its core, voluntary consent underscores the necessity for the alleged victim’s decision to be a product of their genuine free will, uninfluenced by external coercions or misleading circumstances. In essence, it is the clear and unambiguous expression of a person’s agreement or permission regarding a particular action or situation. Without such willful affirmation, the foundation of the defense crumbles. External pressures, whether subtle or overt, compromise the authenticity of the consent given. The mere presence of duress, threats, or any form of deception can immediately strip away the veneer of voluntariness, transforming what might have appeared as agreement into a coerced acquiescence.

Further complicating the landscape of consent is the issue of intoxication. When an individual is under the influence of alcohol or drugs, their cognitive faculties are impaired, affecting their judgment, understanding, and decision-making abilities. As a result, many jurisdictions take the stance that an intoxicated individual lacks the capacity to give informed, conscious consent. The underlying rationale is clear: if one’s mental state is clouded or compromised, they cannot fully grasp the ramifications of their decisions or the situations they might be consenting to. Thus, any consent provided in such states is viewed with skepticism and is often deemed legally void, ensuring that the sanctity and integrity of true, voluntary consent remain unblemished.

MPC and Limitations on Consent Defense

The Model Penal Code (MPC), serving as a guide for many jurisdictions, has taken a particularly cautious approach to the defense of consent. Its circumscribed view centers around two primary conditions. Firstly, the defense is tenable only if the bodily harm resulting from the consented conduct is not deemed serious. This criterion reflects the MPC’s intent to ensure that the defense doesn’t get exploited to justify grievous harms or offenses. The underlying principle is that, while individuals have a certain autonomy over their own bodies, there is a societal interest in preventing serious harm, even if a person consents to such harm.

Secondly, the MPC extends the defense to scenarios where the harm or the conduct leading to it is a predictable risk associated with lawful athletic competitions or sports. This provision acknowledges the inherent risks that participants willingly undertake in such activities. For instance, in sports like rugby or boxing, injuries, sometimes severe, are par for the course. However, it’s essential to note that the MPC emphasizes the term “lawful” athletic contests, suggesting that the activities must conform to established rules and standards. This implies that any harm that goes beyond the accepted norms of the sport, even if it’s an accident, might not fall under the purview of this defense.


Consent can be a defense against allegations of criminal behavior, especially in sex-related crimes like rape. In contact sports, participants are assumed to have given consent to potential injuries, but this doesn’t apply if severe harm or death is probable. Consent must be given knowingly and willingly. If someone is unable to give informed consent due to legal incompetence, age, mental state, or intoxication, the defense becomes ineffective. Being under the influence of drugs or alcohol clouds judgment, making many jurisdictions reject such consent as invalid. The Model Penal Code (MPC) provides a restrictive view on consent as a defense. It only allows the defense if the resulting harm isn’t severe or if the harm is a foreseeable risk in lawful sports. The MPC aims to prevent misuse of the defense in justifying grave harms and emphasizes that sports activities should adhere to standard rules for the defense to be applicable.

References and Further Reading

Justification: Theory.” Encyclopedia of Crime and Justice.

Justification: Self-Defense.Encyclopedia of Crime and Justice.

Justification: Law Enforcement.Encyclopedia of Crime and Justice.

Justification: Necessity.” Encyclopedia of Crime and Justice.

23 Other States Have ‘Stand Your Ground’ Laws, Too.”  (2012). The Atlantic.  


Coker v. Georgia, 433 U.S. 584 (1977).

Graham v. Connor, 490 U.S. 386, 396–397 (1989).

Tennessee v. Garner, 471 U.S. 1, 11–12 (1985).

U.S. v. Cortez, 449 U.S. 411, 417 (1981).

United States v. Dunn, 480 U.S. 294 (1987)

Modification History

File Created:  07/17/2018

Last Modified:  09/26/2023

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This work is licensed under an Open Educational Resource-Quality Master Source (OER-QMS) License.

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