§ 16.068.Amended and Supplemental Pleadings

The relation-back rule, and it is drafted generously.

Where a filed pleading relates to a claim or defence not subject to a plea of limitation when filed, a later amendment or supplement that changes the facts or grounds of liability or defense is not subject to a plea of limitation — unless it is wholly based on a new, distinct, or different transaction or occurrence.

"Wholly" is the word that decides cases. An amendment sharing any part of its factual basis with the original pleading relates back. Only one resting entirely on separate events falls outside.

That is a low bar, and deliberately so. A plaintiff learns things in discovery, and a rule requiring every legal theory to be pleaded within the limitations period would force defensive over-pleading at the outset.

The provision covers defences as well as claims, and cross actions and counterclaims alongside them. A defendant who develops a new ground of defence is protected on the same terms.

The opening condition is the real limit. The original pleading must have been not subject to a plea of limitation when it was filed. Relation back rescues an amendment to a timely suit; it does nothing for a suit that was late to begin with.

A new legal theory on the same facts is not a new transaction. Recasting negligence as gross negligence, or adding a statutory claim arising from the same events, relates back — the section speaks of changing "the grounds of liability", which is exactly that.

Adding a new party is a different question the section does not answer, and one governed by the case law on misnomer and misidentification rather than by this text.

The counterclaim provision that follows deals separately with a claim asserted in response to a suit filed near the end of the period.