Principle of res-judicata between co-defendants. How res-judicata differs from Res-Subjudice and estoppel

 Explain the principle of res-judicata between co-defendants. How res-judicata differs from res-subjudice and estoppel? UK22

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I. Principle of Res Judicata between Co-Defendants

Res Judicata is embodied under Section 11 of the Code of Civil Procedure, 1908 (CPC). It bars re-litigation of matters already finally decided between the same parties.

Res Judicata between Co-defendants:

Though res judicata generally applies between the same parties, in exceptional circumstances, it can apply between co-defendants, provided the following conditions are fulfilled:

Conditions (Laid down in Munshi Ram v. Radha Kishan, AIR 1975 SC 2216):

1. There must be a conflict of interest between the co-defendants.

2. It must be necessary to resolve that conflict for the decision in the former suit.

3. The court must have adjudicated upon it expressly.

4. The decision must be final and binding.

Example:

If in a previous suit between A, B, and C, the court determines that B, and not C, has title to a property, then in a subsequent suit between B and C over the same property, res judicata may operate if the conditions are met.

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II. Difference between Res Judicata, Res Sub Judice, and Estoppel

Principle	Provision	Meaning	Stage of Applicability	Basis of Bar	Key Case/Illustration
Res Judicata	Section 11, CPC	Prevents re-litigation of the same issue finally decided	After final judgment	Final adjudication between same parties on same issue	Satyadhyan Ghosal v. Deorajin Debi
Res Sub Judice	Section 10, CPC	Prevents parallel proceedings in two courts over the same matter	During pendency of suit	Avoids conflicting decisions and multiplicity of suits	National Institute of Mental Health v. C. Parameshwara
Estoppel	Section 115, Indian Evidence Act, 1872	Prevents a party from denying what he has previously represented	Procedural tool applied during proceedings	Prevents inconsistent conduct causing prejudice	Pickard v. Sears (UK); B.L. Sreedhar v. K.M. Munireddy, AIR 2003 SC 578

Conclusion:

While res judicata ensures finality of litigation, res sub judice prevents parallel litigation. Estoppel, on the other hand, is a rule of evidence that binds a party to a prior admission or conduct. The principle of res judicata between co-defendants ensures that an issue once decided conclusively between them is not reopened, provided strict criteria are satisfied, thus preserving judicial economy and consistency.