Illinois self-defense law is built on the principle of “reasonableness.” To lawfully use force, you must have a reasonable belief that it is necessary to protect yourself or another from the imminent use of unlawful force. This belief is judged by what an average person would consider reasonable in the same situation, not just your personal perception.
Imminent Threat and Proportionality
The threat you respond to must be imminent—meaning immediate and unavoidable. You cannot use self-defense against a threat that might happen in the future or against law enforcement officers performing their duties.
The force you use must be proportional to the threat. For example, non-lethal force is appropriate for minor threats, while deadly force is only justified if you reasonably believe it is necessary to prevent imminent death, great bodily harm, or a forcible felony such as robbery, assault, or burglary.
Duty to Retreat and the Castle Doctrine
Illinois does not have a broad “stand your ground” law. In public places, you have a duty to retreat if it is safe to do so before using force, especially deadly force. However, the law is different in your home. Under the “castle doctrine,” you do not have to retreat if you are threatened inside your home. You may use force—including deadly force—if you reasonably believe it is necessary to prevent an intruder from causing harm or committing a violent felony.
Defense of Others and Property
You may use force to defend another person if you reasonably believe it is necessary to protect them from imminent unlawful force. Force can also be used to prevent unlawful entry onto your property, but deadly force is only justified if you believe it is necessary to prevent a forcible felony or if the entry is violent.
Legal Self-Defense Weapons
Illinois allows several self-defense tools, including:
Firearms (with a valid FOID card and, for concealed carry, the appropriate license)
Pepper spray
Stun guns or Tasers (with a valid FOID card)
Common household items in emergencies
Key Takeaways
You must have a reasonable belief of imminent and unlawful threat.
Force must be proportional to the threat faced.
In public, retreat if safe; at home, you may stand your ground.
Deadly force is only justified to prevent death, great bodily harm, or a forcible felony.
Specific weapons are legal for self-defense if you meet state requirements.
Understanding these rules can help you protect yourself lawfully and avoid unintended legal consequences in Illinois.
Sources
[1] https://www.cheronislaw.com/blog/2024/05/navigating-self-defense-laws-in-illinois/
[2] https://hbtsecuritygroup.com/protecting-yourself-and-your-loved-ones-a-guide-to-illinois-self-defense-laws/
[3] https://geneognibeneassociates.com/criminal-law-basics/what-are-the-rules-on-self-defense-in-illinois/
[4] https://www.findlaw.com/state/illinois-law/illinois-self-defense-laws.html
[5] https://hirschlawgroup.com/illinois-self-defense-laws/
