What's bolded states that you can use force against any other type of unlawful force. If it does not fall under the subsections (1)(2)(3), you lose your automatic presumption of reasonableness, but it can still be found to be reasonable.Sec. 9.31. SELFDEFENSE.
(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.
What's bolded here is that deadly force is lawful if you are found reasonable under 9.31, and if someone is committing one of the specific acts listed in (2)(A)(B). The use of deadly force for any other act against you is not lawful, period. Your use of deadly force can still be found reasonable even if you don't meet the automatic presumptions in (b), as long as something in (2)(A)(B) is occurring against you.Sec. 9.32. DEADLY FORCE IN DEFENSE OF PERSON. (a) A person is
justified in using deadly force against another:
(1) if the actor would be justified in using force against
the other under Section 9.31; and
(2) when and to the degree the actor reasonably believes
the deadly force is immediately necessary:
(A) to protect the actor against the other's use or
attempted use of unlawful deadly force; or
(B) to prevent the other's imminent commission of
aggravated kidnapping, murder, sexual assault, aggravated sexual
assault, robbery, or aggravated robbery.
(b) The actor's belief under Subsection (a)(2) that the deadly
force was immediately necessary as described by that subdivision is
presumed to be reasonable if the actor:
(1) knew or had reason to believe that the person against
whom the deadly 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 an offense
described by Subsection (a)(2)(B);
(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.
(c) A person who has a right to be present at the location where
the deadly force is used, who has not provoked the person against whom
the deadly force is used, and who is not engaged in criminal activity
at the time the deadly force is used is not required to retreat before
using deadly force as described by this section.
(d) For purposes of Subsection (a)(2), in determining whether an
actor described by Subsection (c) reasonably believed that the use of
deadly force was necessary, a finder of fact may not consider whether
the actor failed to retreat.
As far as duty to retreat, section (d), it says that if you meet those requirements the jury can't consider whether or not you failed to retreat. However, it does not say that you have a duty to retreat if you don't meet that clause.