Texas Code of Criminal Procedure - CRIM P Art. 35.15. Number of challenges

(a) In capital cases in which the State seeks the death penalty both the State and defendant shall be entitled to fifteen peremptory challenges. Where two or more defendants are tried together, the State shall be entitled to eight peremptory challenges for each defendant; and each defendant shall be entitled to eight peremptory challenges.

(b) In non-capital felony cases and in capital cases in which the State does not seek the death penalty, the State and defendant shall each be entitled to ten peremptory challenges. If two or more defendants are tried together each defendant shall be entitled to six peremptory challenges and the State to six for each defendant.

(c) The State and the defendant shall each be entitled to five peremptory challenges in a misdemeanor tried in the district court and to three in the county court, or county court at law. If two or more defendants are tried together, each defendant shall be entitled to three such challenges and the State to three for each defendant in either court.

(d) The State and the defendant shall each be entitled to one peremptory challenge in addition to those otherwise allowed by law if one or two alternate jurors are to be impaneled and two peremptory challenges if three or four alternate jurors are to be impaneled. The additional peremptory challenges provided by this subsection may be used against an alternate juror only, and the other peremptory challenges allowed by law may not be used against an alternate juror.