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.