Tex. R. Civ. P. 243
As amended through August 27, 2024
If the cause of action is unliquidated or be not proved by an instrument in writing, the court shall hear evidence as to damages and shall render judgment therefor, unless the defendant shall demand and be entitled to a trial by jury in which case the judgment by default shall be noted, a writ of inquiry awarded, and the cause entered on the jury docket.
Tex. R. Civ. P. 243