If π (Vermont) sues ∆1 and ∆2 (both from Kentucky) for a ski incident, is a claim from ∆1 against π a compulsory counterclaim?

The correct answer indicates that the claim from ∆1 against π is a compulsory counterclaim because it arises from the same event as the original claim brought by π. In procedural terms, a compulsory counterclaim is one that must be filed in response to the opposing party's claim if it pertains to the same transaction or occurrence.

In this scenario, the ski incident is the focal point of both the plaintiff's claim and the defendant's counterclaim. The rationale behind this rule is to promote judicial efficiency by ensuring that all related claims are resolved in a single proceeding, avoiding multiple lawsuits that could lead to inconsistent judgments and increased litigation costs.

Moreover, if a compulsory counterclaim is not raised in the current litigation, it may be barred in future suits due to the doctrine of res judicata, which prevents parties from relitigating claims that could have been brought in previously adjudicated actions. This further emphasizes the importance of considering whether claims arise from the same event when determining if a counterclaim is compulsory.

The options that suggest the claim can be filed later or is unrelated lack recognition of the transactional relationship between the original claim and the counterclaim, thereby missing the essential requirement that is characteristic of compulsory counterclaims.