I have spent most of my life in Texas. I was born here and have lived here for nearly 36 years with the exception of an odd year or two out of state while in school. When I talk with other criminal defense lawyers (or really anyone!) who does not live in Texas, one aspect of our law seems to be of primary interest to non-Texans: self-defense.
Self-Defense
Under Texas law, a person is legally justified in using force against another person when the person reasonably believes using force is immediately necessary to protect the person. A couple of qualifiers exist here: first, the level of force used to defend must be proportional to the force the person is defending from—meaning, you generally can’t begin beating someone with a baseball bat who you believe is about to slap you. Second, note that a person has to believe it is “immediately necessary” to use force to defend. Critically, the use of force for self-defense is NEVER justified by words alone—self-defense has to be against an immediate, physical threat. And, of course, you cannot employ self-defense if you are acting illegally; meaning, if I break into someone’s house, I cannot use self-defense as a legal justification to fight back if the homeowner begins beating me.
Deadly Force
Importantly, this includes the right to use deadly force in self-defense, where the person’s attacker is using deadly force (and subject to all the above requirements.) Again, this is the idea of proportionality—no bats or guns during a fistfight.
Commonly, non-Texans want to know if Texas law really permits a person to use deadly force against someone who breaks into the person’s home. The answer is that unlawfully entering into a person’s home (i.e. breaking into a home) provides a presumption that the use of deadly force was immediately necessary. Meaning, you can generally presume use of deadly force is legally justified if someone breaks into your home under Texas law. So the short answer is “yes, the majority of the time.”
Defense of Third Persons (I.e. Other People)
In Texas, a person can use deadly force to protect another person if the person would themselves be justified in using deadly force in the situation (see above), and the person reasonably believes that intervention is necessary to protect the other person. As you may well have heard, there is “no duty to retreat” in Texas. This is because of the “immediately” phrasing in the statute; if the use of force is required immediately—as it is under Texas law—requiring a person to attempt to retreat first before using force to defend would make no sense.
Mutual Combat
The use of force against another person is never legally justified if the person consented to exact force used against him. So, for example, if two people meet in the parking lot to fight, and the fight remains weapon-free (generally speaking), neither party can claim self-defense as a justification, because they agreed to fight.
This is similar to the idea of “mutual combat.” Mutual combat refers to the idea that where two people agree to fight, and they do meet and do fight, the person who gets the worse end of the fight cannot generally claim they have been assaulted. Why not? You don’t get to agree to a fight and then complain if you lose. Under the Texas Penal code, a person’s consent to fight (or the other person’s reasonable belief that the person had consented to fight) is a defense to assault, so long as serious bodily injury was not inflicted. You cannot consent, in any fashion, to be beaten severely or killed. (And that’s probably a good idea.)