Why can different laws apply to different issues in the same court case?

In the context of conflict of laws, it is common for different laws to apply to different issues within a single court case through a process known as dépeçage (French for "breaking into smaller pieces").1

This practice occurs because courts may determine the applicable law on an issue-by-issue basis rather than applying a single jurisdiction's law to the entire dispute. By "splitting" a case into its various component parts, a court can select the most appropriate legal rule for each specific question, which may promote more just outcomes in complex international or multi-jurisdictional cases.1

While this approach allows for tailored legal analysis, it also presents significant challenges:
* Increased Burden: It places a greater administrative burden on both the court and the involved parties.1
* Reduced Precedent: It can diminish the value of a decision as a precedent for future cases, as the specific combination of laws applied may be unique to that case.1
* Complexity: Because criteria for choosing these laws—such as the "most significant relationship"—are not strictly ranked, different courts may reach divergent results, leading to uncertainty.1