In a brief opinion issued yesterday, written by Chief Judge Easterbrook, the Seventh Circuit articulates the rule that a Rule 8(c)(1) affirmative defense cannot be raised by a Rule 12(b)(6) motion. The particular defense at issue here was Indiana’s two-year statute of limitations, which seemed to the district court to block the prisoner-plaintiff’s § 1983 claim against prison administrators for having ignored his medical condition.

Judge Easterbrook concedes that occasions arise in which the plaintiff says so much about the subject of the affirmative defense in the complaint as to show that the defense is airtight. Then, he concedes, the defendant can properly file a Rule 12(c) motion for judgment on the pleadings. But otherwise, he says that the defendant has to raise the defense in the answer, which, of course, opens the possibility of discovery—avoiding which is the whole reason to try to move under Rule 12 in the first place.

There are exceptions to the rule that affirmative defenses may not be raised by motion—described in Rule 12(b)—of which failure to state a claim is the most frequently used. Failure to join a necessary party can also be raised by motion. Rule 12(b)(7). The others are the so-called dilatory defenses (jurisdiction, venue, service, Rule 12(b)(2)-(5)), which must be raised by motion or in the answer, or be waived. Rule 12(h).

I’ll note that Wisconsin’s rules allow four affirmative defenses to be raised by motion that Rule 12(b) does not permit: lack of capacity to sue or be sued; res judicata; statute of limitations (so that a case like this one arguably would have come out differently in a Wisconsin state court); and another action pending between the same parties for the same cause. Wis. Stat. § 802.06(2)(a) 1., 8.-10.