                            In the
United States Court of Appeals
              For the Seventh Circuit
                         ____________

No. 01-1346
MARVIN D. GLEASH, SR.,
                                            Plaintiff-Appellant,
                               v.

MICHAEL YUSWAK, et al.,
                                         Defendants-Appellees.
                         ____________
       Appeal from the United States District Court for the
         Northern District of Illinois, Western Division.
         No. 00 C 50435—Philip G. Reinhard, Judge.
                         ____________
   ARGUED OCTOBER 2, 2002—DECIDED OCTOBER 21, 2002
                     ____________


 Before BAUER, EASTERBROOK, and ROVNER, Circuit
Judges.
  EASTERBROOK, Circuit Judge. Marvin Gleash has filed
two essentially identical suits complaining that prison
guards violated the eighth amendment by confiscating a
back brace that the prison’s medical staff had provided. The
district court dismissed the first suit with prejudice un-
der 28 U.S.C. §§ 1915(e)(2)(B)(ii) and 1915A(b)(1) for fail-
ure to state a claim on which relief may be granted. The
judge viewed the complaint as challenging the medical
staff’s delay in furnishing a replacement; that grievance,
the judge stated, alleges only negligence and thus does
not state a constitutional claim. See Farmer v. Brennan,
511 U.S. 825 (1994); Estelle v. Gamble, 429 U.S. 97 (1976).
2                                             No. 01-1346

Gleash timely sought reconsideration, pointing out that
his principal allegation—which the judge had not men-
tioned—was that the guards should not have taken his
brace in the first place. The judge denied this motion
without comment. Gleash did not appeal. Instead, a little
more than five months later, he filed a second action
making the same allegations. The same judge who had
handled the first action dismissed the second before the
defendants had been served with process, observing that
a suit “duplicative of a parallel action already pending
in another federal court” may be dismissed. This time
Gleash appealed.
   The judge’s first decision is problematic because it did
not come to grips with Gleash’s principal contention. Con-
fiscation of a medical device for no reason other than to
inflict pain violates the eighth amendment. Moreover,
the judge’s second decision cannot be sustained on the
ground that he gave. No rule of federal law requires the
dismissal of a second or successive civil suit, even if an-
other concerning the same controversy is pending. Colora-
do River Water Conservation District v. United States,
424 U.S. 800 (1976), and Kerotest Manufacturing Co. v.
C-O-Two Fire Equipment Co., 342 U.S. 180 (1952), show
that a federal judge may stay an action when some other
suit offers the advantage of a speedy and comprehensive
solution, but that does not describe Gleash’s situation. No
other suit was pending when the second was dismissed.
Even when prudence calls for putting a redundant suit
on hold, it must be stayed rather than dismissed un-
less there is no possibility of prejudice to the plaintiff.
See Deakins v. Monaghan, 484 U.S. 193, 202-04 (1988);
Central States Pension Fund v. Paramount Liquor Co.,
203 F.3d 442 (7th Cir. 2000); Blair v. Equifax Check
Services, Inc., 181 F.3d 832, 838-39 (7th Cir. 1999).
  Yet although the district court’s explanation was defi-
cient, its judgment may be correct. Gleash’s first suit was
No. 01-1346                                               3

over, and a renewal may be dismissed on the ground
of claim preclusion (res judicata) even if the decision in
the first was transparently erroneous. See Federated De-
partment Stores, Inc. v. Moitie, 452 U.S. 394 (1981). If,
as Gleash’s appellate counsel contends, the court should
have dismissed the first complaint rather than the first
suit (a step that would have allowed refiling), the fact
remains that this is not what happened. The final deci-
sion terminated the suit. In civil litigation, the final
resolution of one suit is conclusive in a successor, whether
or not that decision was correct. If Gleash wanted to con-
test the validity of the district judge’s decision—either on
the merits or on the ground that he should have been
allowed to re-plead—he had to appeal.
  One potential response might be that claim preclu-
sion is an affirmative defense, which judges should not
entertain when conducting pre-service screening under
§§ 1915(e)(2)(B) and 1915A. Briefing this question at our
request, Gleash’s counsel commendably replied that a
court that has discretion to raise affirmative defenses on
its own after service, see Arizona v. California, 530 U.S.
392, 412-13 (2000), has the same discretion before ser-
vice. Both §1915(e)(2)(B)(iii) and §1915A(b)(2) require the
judge to consider official immunity, which is an affirma-
tive defense. See Gomez v. Toledo, 446 U.S. 635, 640
(1980). This implies that other affirmative defenses are
open too. So we held in Walker v. Thompson, 288 F.3d
1005, 1009-10 (7th Cir. 2002), adding that the judge
should invoke an affirmative defense (on behalf of po-
tential defendants who have not had a chance to do so
themselves) only if it is so plain from the language of the
complaint and other documents in the district court’s files
that it renders the suit frivolous. That standard was
met here, because all of the proceedings in the first suit
occurred before the same judge, who therefore did not
need to guess what those records would show. Under the
4                                               No. 01-1346

circumstances there was no point to serving the defen-
dants with process, forcing them to engage counsel, and
then waiting for the inevitable motion to dismiss on pre-
clusion grounds. It was sensible to stop the suit immedi-
ately, saving time and money for everyone concerned.
See Denton v. Hernandez, 504 U.S. 25 (1992); Neitzke v.
Williams, 490 U.S. 319, 324 (1989).
  Only one way out has been suggested: Gleash’s appel-
late counsel contends that the district judge should have
treated the second complaint not as an independent suit
but as a motion for relief under Fed. R. Civ. P. 60(b)(6) in
the initial (and thus the only) suit. Although the point is
well argued, it cannot prevail. True enough, courts give
effect to the substance of a document and not to its caption.
See, e.g., Smith v. Barry, 502 U.S. 244 (1992) (appellate
brief may be treated as a notice of appeal if it contains
all matters essential to a notice of appeal); Godoski v.
United States, No. 02-1412 (7th Cir. Sept. 23, 2002) (peti-
tion for a writ of error coram nobis properly treated as
a collateral attack under 28 U.S.C. §2255). But the sub-
stance of this document matched its caption. Complaints
state claims, while motions under Rule 60(b) state reasons
for modification. The document that Gleash filed was a
claim, not a request (with reasons) for alteration. Even pro
se litigants must follow the rules. See McNeil v. United
States, 508 U.S. 106 (1993). Just as a letter is not a com-
plaint, see Baldwin County Welcome Center v. Brown, 466
U.S. 147 (1984), so a complaint is not a motion in a prior
and unnamed case. The civil rules distinguish “pleadings”
from motions, and this was a “pleading.” That much of
form must be respected, given the many rules (includ-
ing timing and answer requirements) for pleadings, which
differ substantially from the timing and form rules for
motions. Otherwise litigation is chaos.
 Anyway, it would do Gleash no good to treat this as a
Rule 60(b) motion, not only because appellate review is
No. 01-1346                                                5

deferential, see Metlyn Realty Corp. v. Esmark, Inc., 763
F.2d 826 (7th Cir. 1985)—and a district judge does not
abuse his discretion by failing to do something he was
never even asked to do—but also because legal error is not a
proper ground for relief under Rule 60(b). That rule
is designed to allow modification in light of factual infor-
mation that comes to light only after the judgment, and
could not have been learned earlier. See Central States
Pension Fund v. Central Cartage Co., 69 F.3d 1312 (7th
Cir. 1995). A contention that the judge erred with respect
to the materials in the record is not within Rule 60(b)’s
scope, else it would be impossible to enforce time limits
for appeal. What Gleash really wants is to take a long-
delayed appeal from the district judge’s initial order, using
Rule 60(b) to reopen the window. That is not a proper use
of the rule, as appellate counsel concedes. See Bell v.
Eastman Kodak Co., 214 F.3d 798, 801 (7th Cir. 2000);
Neuberg v. Michael Reese Hospital Foundation, 123 F.3d
951, 955 (7th Cir. 1997). Indeed, even a post-judgment
change of law does not allow relief under Rule 60(b). See
Norgaard v. DePuy Orthopaedics, Inc., 121 F.3d 1074 (7th
Cir. 1997).
   Counsel contends that prisoners’ suits should be handled
differently because erroneous orders under §§ 1915(e)(2)(B)
and 1915A may be counted against a prisoner’s limit of
three frivolous suits or appeals in forma pauperis. See
28 U.S.C. §1915(g). The district judge stated that Gleash’s
initial complaint was one of these “strikes.” That nota-
tion is no more than a housekeeping matter, however;
whether a prisoner is disqualified under §1915(g) must
be determined by the court in which the fourth action is
filed. See Evans v. Illinois Department of Corrections, 150
F.3d 810 (7th Cir. 1998).
  For what it may be worth, our view of this matter dif-
fers from the district judge’s: Gleash’s first suit was not
frivolous and does not count against the limit of three. But
6                                            No. 01-1346

his second suit, squarely barred by claim preclusion, is
frivolous. This appeal is not itself frivolous; we did not
determine until after Gleash filed his notice of appeal
that district judges are entitled to dismiss (before ser-
vice) on account of affirmative defenses other than im-
munity. See Walker, 288 F.3d at 1009-10. What is more,
the district judge’s stated reason for dismissal was er-
roneous, so an appeal could not be deemed frivolous. The
bottom line is that Gleash has accumulated one “strike”
over the course of the two suits and one appeal.
                                               AFFIRMED

A true Copy:
      Teste:

                       ________________________________
                       Clerk of the United States Court of
                         Appeals for the Seventh Circuit




                  USCA-02-C-0072—10-21-02
