The fact pattern
Read it twice before you look at the answer
Two plaintiffs, both citizens of State X, sue two defendants in federal court. Defendant 1 is a citizen of State Y; Defendant 2 is a corporation incorporated in State Z with its principal place of business in State X. Plaintiff 1 claims $90,000 in damages; Plaintiff 2 claims $40,000 arising from the same incident. The plaintiffs invoke diversity jurisdiction. The defendants move to dismiss for lack of subject-matter jurisdiction.
Try it before you scroll
Spend 15 minutes writing your own IRAC answer first: the model below is far more useful after you have committed to your own issue list. These issues are in the facts:
- Complete diversity (the Strawbridge rule)
- Corporate citizenship: incorporation and principal place of business
- Amount-in-controversy threshold ($75,000)
- Whether claims can be aggregated
Model IRAC answer
One way to write it, not the only way. Compare it to yours.
Issue
Whether the federal court has diversity jurisdiction when one defendant shares State X citizenship with both plaintiffs and one plaintiff's claim falls below $75,000.
Rule
Diversity jurisdiction under 28 U.S.C. § 1332 requires complete diversity (no plaintiff may be a citizen of the same state as any defendant) and an amount in controversy exceeding $75,000. A corporation is a citizen both of its state of incorporation and of the state where it has its principal place of business. A single plaintiff may aggregate multiple claims against a single defendant to meet the amount, but multiple plaintiffs generally may not aggregate separate claims to cross the threshold, though supplemental jurisdiction may sometimes reach a co-plaintiff's smaller related claim once one plaintiff independently satisfies the amount.
Application
Complete diversity fails. Defendant 2 is a corporation with its principal place of business in State X, making it a citizen of both State Z and State X. Because both plaintiffs are citizens of State X, there is a State X citizen on both sides of the case. Under the complete-diversity rule, that defeats § 1332 jurisdiction regardless of the amount in controversy.
Even setting citizenship aside, the amount analysis is split. Plaintiff 1's $90,000 claim independently exceeds $75,000. Plaintiff 2's $40,000 claim does not, and two plaintiffs cannot aggregate separate claims to manufacture the threshold. Plaintiff 2 might attempt to ride along on supplemental jurisdiction, but that question never arises here because the citizenship defect is dispositive.
Conclusion
There is no diversity jurisdiction. Defendant 2's State X principal place of business destroys complete diversity with the State X plaintiffs, so the court must dismiss for lack of subject-matter jurisdiction; the amount-in-controversy question is moot.
Verify before you rely on this. This is an original teaching example, not legal advice. Rules vary by jurisdiction and by your professor's framing: check every rule statement against your casebook and class notes before using it.
Now try it timed.
Open the IRAC Practice Gym, set a 15-minute timer, and write your own answer to this fact pattern. You get feedback that helps you think, never an answer written for you.