http://www.statutes.legis.state.tx.us/SOTWDocs/PE/htm/PE.9.htm
Sec. 9.31. SELF-DEFENSE. (a) Except as provided in Subsection (b), a person is justified in using force against another when and to the degree the actor reasonably believes the force is immediately necessary to protect the actor against the other's use or attempted use of unlawful force. The actor's belief that the force was immediately necessary as described by this subsection is presumed to be reasonable if the actor:
(1) knew or had reason to believe that the person against whom the force was used:
(A) unlawfully and with force entered, or was attempting to enter unlawfully and with force, the actor's occupied habitation, vehicle, or place of business or employment;
(B) unlawfully and with force removed, or was attempting to remove unlawfully and with force, the actor from the actor's habitation, vehicle, or place of business or employment; or
(C) was committing or attempting to commit aggravated kidnapping, murder, sexual assault, aggravated sexual assault, robbery, or aggravated robbery;
(2) did not provoke the person against whom the force was used; and
(3) was not otherwise engaged in criminal activity, other than a Class C misdemeanor that is a violation of a law or ordinance regulating traffic at the time the force was used.
(b) The use of force against another is not justified:
(1) in response to verbal provocation alone;
(2) to resist an arrest or search that the actor knows is being made by a peace officer, or by a person acting in a peace officer's presence and at his direction, even though the arrest or search is unlawful, unless the resistance is justified under Subsection (c);
(3) if the actor consented to the exact force used or attempted by the other;
(4) if the actor provoked the other's use or attempted use of unlawful force, unless:
(A) the actor abandons the encounter, or clearly communicates to the other his intent to do so reasonably believing he cannot safely abandon the encounter; and
(B) the other nevertheless continues or attempts to use unlawful force against the actor; or
(5) if the actor sought an explanation from or discussion with the other person concerning the actor's differences with the other person while the actor was:
(A) carrying a weapon in violation of Section 46.02; or
(B) possessing or transporting a weapon in violation of Section 46.05.
(c) The use of force to resist an arrest or search is justified:
(1) if, before the actor offers any resistance, the peace officer (or person acting at his direction) uses or attempts to use greater force than necessary to make the arrest or search; and
(2) when and to the degree the actor reasonably believes the force is immediately necessary to protect himself against the peace officer's (or other person's) use or attempted use of greater force than necessary.
(d) The use of deadly force is not justified under this subchapter except as provided in Sections 9.32, 9.33, and 9.34.
(e) A person who has a right to be present at the location where the force is used, who has not provoked the person against whom the force is used, and who is not engaged in criminal activity at the time the force is used is not required to retreat before using force as described by this section.
(f) For purposes of Subsection (a), in determining whether an actor described by Subsection (e) reasonably believed that the use of force was necessary, a finder of fact may not consider whether the actor failed to retreat.
