Eduardo Perazza de Medeiros and Leandro Gouveia Felix 

Although it has kept the limitation on the res judicata to the terms of the decision that rules on the merits, in whole or in part, the new Brazilian Code of Civil Procedure (CPC) has extinguished the incidental declaratory action, extending its effects also to the incidental issue, provided that the following requirements are met: (i) its resolution must depend on a judgment on the merits; (ii) it must have been submitted to previous and effective adversary proceedings; (iii) the court must have jurisdiction on the matter and the person to resolve it as the main issue, and (iv) there must be no cognizance restrictions or limitations, preventing a further analysis of the incidental issue - as may occur in writs of mandamus and actions filed with special courts.

In simple terms, the new CPC allows the res judicata to, exceptionally, extrapolate the main subject to also make other incidental issues immutable. If, on the one hand, this legislative choice should generate procedural economy and give greater effect to the decisions rendered by the judge, on the other hand, because it is a complex technical procedural aspect that is hard to identify in actual cases, it should generate discussions and impose practical challenges, particularly to lawyers.

There are two points that have already caused great debate. The first relates to the coverage of the res judicata as regards the incidental issue: after all, will only the decision or also its grounds become res judicata? The second refers to the case of the main issue being decided in favor of a party, but not the incidental issue: will the winning party need to appeal against the decision that was favorable to him in order to prevent the formation of res judicata?

These are some examples of questions that still have no definitive answer. Until they are definitively resolved by the Federal Supreme Court - which will take years - litigation lawyers may be required to use greater caution in order to delimit the controversial points of the dispute, specifically refuting incidental issues, preferably in a specific topic. In addition, extra attention will be required in the analysis of decisions on the merits, especially for the filing of motions for clarification of judgment, and especially if the incidental issue is not expressly judged in the decision and for the analysis about the existence of any appealable matter, even if the main issue has been ruled favorably.