Tex. R. Civ. P. 809
As amended through August 27, 2024
Nothing in these rules relating to trespass to try title shall be so construed as to alter, impair or take away the rights of parties, as arising under the laws in force before the introduction of the common law, but the same shall be decided by the principles of the law under which the same accrued, or by which the same were regulated or in any manner affected.
Tex. R. Civ. P. 809