X and Y litigated a suit on the question of title which was heard and finally decided by a competent court. Y later files a fresh suit on the same issue against
X. The subsequent suit is barred by:

Explanation: Section 11 of the CPC enacts res judicata: no court shall try any suit or issue in which the matter directly and substantially in issue has already been decided by a court competent to try the subsequent suit, between the same parties or persons claiming under them. Once decided, the parties are concluded by the judgment, and re-litigation of the same matter is barred. Res sub judice (Section 10) is different - it stays a later suit pending an earlier one, and does not bar it permanently. Lis pendens and caveat serve other purposes. Here the matter is finally decided, so res judicata applies.