with whom LAVENDER, and SIMMS, JJ, join, dissenting.
Today the court affirms the judgment on jury verdict in a manufacturer’s products liability action and pronounces that [1] the defendant sufficiently preserved claimed errors for appellate review; [2] the trial court correctly excluded certain midtrial evidence; [3] the trial court’s refusal to give a specially tailored instruction concerning the misuse defense was not error; and [4] the amount of damages awarded by the jury was not excessive.
I must recede from the court’s affirmance of the judgment. In trials of legal actions the district court must sua sponte charge the jury on all critical issues in the case. Its failure to discharge this responsibility is a ground for new trial. Because the instructions given by the trial court were not tailored to the material issues raised by evidence admitted without objection, the essence of the manufacturer’s defense was never communicated to the fact triers. I would reverse the judgment and remand the case for a new trial.
I
THE ANATOMY OF LITIGATION
While working as a part-time service station attendant, Ronald Treadway [Tread-way] was injured by a tire that exploded when it was being mounted for a customer. Manufactured by Uniroyal Tire Company [Uniroyal], the offending tire was the last of four new ones Treadway was mounting. For mounting the first three tires Tread-way used a machine without incident. While inflating the fourth tire Treadway did not use the mounting machine because a vital piece of that equipment was then elsewhere in use. Instead, Treadway moved the fourth tire to the station’s center island and attempted to inflate it with the aid of an “O” ring. The tire blew when Treadway was reaching across it with an air hose. The explosion, which hurled the tire twenty feet in the air, caused injury to Treadway’s wrist by fracturing three bones, one of which did not respond to treatment. Treadway brought this action against Uniroyal and the retailer. He sought to predicate liability on a manufacturing defect in the tire.
As it did in the trial court so also on appeal Uniroyal ascribes Treadway’s injury to his failure to follow the instructions and warnings printed on the tire’s label. That label directed a user not to: [1] inflate the tire without a mounting machine, [2] lean over the tire while inflating it, and [3] inflate the tire beyond 40 p.s.i. Included in each label was a warning that the user’s failure to follow the instructions could re-*945suit in serious injury. According to undisputed proof, Treadway did not follow the first two of these instructions when inflating the fateful tire, although he was familiar with their content and was aware of the danger from disregarding them.
Based on Treadway’s undisputed failure to follow the warnings on the tire’s label, Uniroyal sought to assert a “misuse” defense. In its jury charge on "misuse of product” the trial court refused to include an explanation of Treadway’s failure to follow the tire mounting instructions. None of the other charges given below mentioned the tire label’s instructions and warnings or the legal effect, if any, of Treadway’s failure to obey them.
II
DEFENDANT’S DEFENSE THAT PLAINTIFF DISREGARDED KNOWN TIRE MOUNTING INSTRUCTIONS AND WARNINGS PRINTED ON THE PRODUCT’S LABEL DOES NOT FALL UNDER THE RUBRIC OF PRODUCT’S “MISUSE”
The trial court instructed generally concerning the defense of misuse in a manufacturer’s products liability action.1 Uniroyal argues it was entitled to an instruction informing the jury that Treadway’s failure to follow the tire mounting instructions could constitute a misuse of the product. Several cases from other states are cited in an effort to persuade this court that the user’s failure to follow known operating instructions can constitute a misuse of the product.2 Whatever may be the law in those jurisdictions, it is clear that on this record a defense of misuse was unavailable to Uniroyal under the Oklahoma norms of strict liability.
In Kirkland v. General Motors Corp.,3 the genesis of manufacturer’s products liability in Oklahoma, we noted that among the permissible strict liability defenses are (1) misuse of a product and (2) voluntary assumption of or exposure to the risk from a known defect or danger. The latter is a variant of the common-law concept known by the Latin maxim of volenti non fit injuria.4 The phrase means that one who voluntarily exposes himself to a known, appreciated and avoidable danger may not recover for injuries occasioned by the expo*946sure.5
In Fields v. Volkswagen of America, Inc.6 we defined a product’s misuse as that use which is not reasonably foreseeable by the manufacturer. Here, it is apparent that Uniroyal could anticipate that consumers would attempt to mount its tires. Assuming Treadway did not follow the known instructions, his conduct — in the context of a products liability claim — could not be considered a misuse but might be viewed as a form of contributory negligence.7 The latter defense is not available in products liability litigation8 when it is sought to be invoked for the plaintiff's “failure to discover the defect in the product, or to guard against the possibility of its existence.”9 On the other hand, “the form of contributory negligence which consists in voluntarily and unreasonably proceeding to encounter a known danger, and commonly passes under the name of assumption of risk," is invocable as a defense sanctioned by § 402A, Restatement (Second) of Torts, as it is in other cases of strict liability.10
*947In short, the court correctly concludes that Uniroyal was not entitled to a jury charge explaining that Treadway’s admitted failure to follow tire mounting instructions and warnings constitutes a product’s “misuse.”
Ill
THE DEFENDANT’S RELIANCE ON THE PLAINTIFF’S DISREGARD OF FAMILIAR TIRE MOUNTING INSTRUCTIONS AND OF THE DANGERS FROM A USER’S NONCOMPLIANCE ENTITLED THE DEFENDANT TO A JURY CHARGE ON VOLUNTARY ASSUMPTION OF THE RISK OF A KNOWN DEFECT AND DANGER
It is undisputed that Treadway did not use a mounting machine to inflate the tire and that he leaned over the tire while inflating it. Both of these actions were in direct contravention of the instructions printed on the label, of whose content he was aware.11 Moreover, Treadway knew that disregarding the warnings could be potentially dangerous. Under these circumstances, Uniroyal was entitled to an instruction on the defense of voluntary assumption of or exposure to the risk of a known defect or danger.12 The evidence clearly called for submission of this defense to the jury. Whenever the legal effect of adequate warnings on the product is an important issue of law in the case, the court has a duty to charge the jury on that issue.13
While Uniroyal did not plead voluntary assumption of risk as one of its defenses in the answer, evidence of Treadway’s failure to heed instructions and warnings that were admittedly known to him was introduced without objection. Moreover, that evidence was relevant upon the general issue of the product’s safety.14 The admission of this evidence, under the law of Oklahoma then in force, operated to amend the answer to make it conform to the proof of voluntary assumption of risk, even though no formal amendment was sought and none was ordered to be made by the trial court,15 In short, the defense, *948though not pleaded in terms of volenti non fit injuña, was an issue in the case because undisputed evidence, admitted sans objection, operates as an amendment of the pleadings.16
By a requested instruction offered under the incorrect label of “misuse”, Uniroyal asked for a jury charge on the legal effect of the plaintiffs disregard of the written instructions and warnings. It also orally asked for the comment j instruction, Restatement (Second) of Torts § 402A, i.e., that a product with a sufficient warning is not unreasonably dangerous.17 Since none of the instructions given below addressed the effect of Treadway’s failure to follow the instructions for mounting the tire, the absence of any charge explaining the defense of voluntary exposure to a known risk must be considered crucial and prejudicial.18 Although Uniroyal did not in iis-*949dem terminis submit to the trial court a requested jury charge on the effect of Treadway’s disregard of known instructions and warnings, the omission is not fatal to the corrective relief sought here. This is so because the trial court clearly had the duty to instruct the jury on this issue. It stood tendered by the evidence admitted without objection and was critical to Uniroyal’s defense of the claim.19 In jury trials of actions at law the district court bears the duty to charge the jury sua sponte on all critical issues in the case, and its failure to carry out this responsibility is a ground for new trial.20
Uniroyal’s critical defense targets Tread-way’s disregard of known instructions and appreciated danger. The instructions given, considered either individually or in toto, clearly lack the contextual tailoring to the evidence presented and issues raised by Uniroyal’s defense to carry a meaningful message to the fact finders.21 In short, the essence of Uniroyal’s response to the claim pressed against it never was communicated to the jury.22
*950A plaintiff’s failure to follow tire mounting instructions has been assessed under several discrete rubrics of analysis germane to a manufacturer’s products liability claim.23 Treadway’s disregard of familiar warnings was indeed relevant to the affirmative defense of voluntary assumption of the risk of a known defect, as well as to the other disputed issues with respect to causation and to the unreasonable dangerousness of the product.24 If the trial court had incorporated the legal effect of Tread-way’s heedless conduct within either its causation or its “unreasonably dangerous” charge, its failure specifically to instruct on assumption-of-risk theory might not have been a reversible error. But because the assumption defense was not included in any of the instructions given, the essential ingredient — nay, the very heart — of Uniroyal’s claim to exoneration from liability for its allegedly defect-free product was obscured and withheld from the fact triers.
I would hence reverse the judgment and remand the case for a new trial.
. Instruction No. 7 embodies the trial court’s charge on misuse of product. It states in pertinent part that:
"* * * Misuse of a product is where the method of using a product was not that which the manufacturer intended or was a use not reasonably anticipated by the manufacturer. If the Plaintiff was using the product in a manner that was foreseeable or could have been anticipated by the Defendant, it is not misuse even if the Plaintiff may have been careless in that use.”
No other jury charge dealt with Treadway’s disregard of the instructions and warnings on the tire.
There is presently no recommended jury charge on misuse of product. See Chapter 12, Products Liability, Uniform Civil Jury Instructions [UCJI 1981].
. Hoffman v. E.W. Bliss Co., 448 N.E.2d 277 [Ind.1983]; Kroon v. Beech Aircraft Corp., 465 F.Supp. 1223 [M.D.Fla.1979], aff'd, 628 F.2d 891 [5th Cir.1980]; Kay v. Cessna Aircraft Co., 548 F.2d 1370 [9th Cir.1977]; Sun Val. Airlines, Inc. v. Avco-Lycoming Corp., 411 F.Supp. 598 [D.Idaho 1976]; Borel v. Fibreboard Paper Products Corporation, 493 F.2d 1076 [5th Cir.1973]; Perfection Paint & Color Company v. Konduris, 147 Ind.App. 106, 258 N.E.2d 681 [1970] and McDev-itt v. Standard Oil Company of Texas, 391 F.2d 364 [5th Cir.1968].
. 521 P.2d 1353, 1366 [Okl. 1974]. See also Fields v. Volkswagen of America, Inc., 555 P.2d 48, 56 [Okl. 1976] and Smith v. United Gypsum Co., 612 P.2d 251, 254 [Okl.1980].
. For an explanation of the volenti doctrine’s historical antecedents, see footnote 8 infra. The maxim volenti non fit injuria, which means that a person who consents to an act is not wronged by it, is predicated on the theory of knowledge and appreciation of the danger and voluntary assent to the risk associated with it. For other jurisdictions discussing the volenti doctrine, see Gray v. E.I. Longyear Company, 78 N.M. 161, 429 P.2d 359, 362 [1967] Halepeska v. Callihan Interests, Inc., 371 S.W.2d 368, 379 [Tex.1963]; Munson v. Bishop Clarkson Memorial Hospital, 186 Neb. 778, 186 N.W.2d 492, 494 [1971]; Walsh v. West Coast Coal Mines, 31 Wash.2d 396, 197 P.2d 233, 238-239 [1948] and Lyons v. Redding Construction Company, 83 Wash.2d 86, 515 P.2d 821, 822-826 [1973]. For Oklahoma cases recognizing the doctrine, see Davis v. Whitsett, 435 P.2d 592, 599 [Okl.1967]; Briscoe v. Oklahoma Natural Gas Company, 509 P.2d 126, 129 [Okl.1973]; Centric Corp. v. Morrison-*946Knudsen Co., 731 P.2d. 411, 419 [Okl.1986]; see also, Black’s Law Dictionary, 5th ed., p. 1412 [1979].
. The volenti doctrine is a universally recognized defense in products liability actions. The proper verbalization of this defense is voluntary assumption of or exposure to the risk of a known defect. Kirkland v. General Motors Corporation, supra note 3 at 1366 and McMurray v. Deere and Company, Inc., 858 F.2d 1436 [10th Cir.1988]. See Annot., Products Liability: Contributory Negligence or Assumption of Risk as Defense Under Doctrine of Strict Liability in Tort, 46 A.L.R.3d 240, 253-256 § 5(a) [1972]; Annot., Distinction Between Assumption of Risk and Contributory Negligence, 82 A.L.R.2d 1218 [1962] and Joseph W. Little, Torts: The Civil Law of Reparation for Harm Done by Wrongful Act, § 9.02, pgs. 435, 442-443 [1985]; see also, Shields v. Morton Chemical Company, 95 Idaho 674, 518 P.2d 857, 859-860 [1974].
. Fields v. Volkswagen of America, Inc., supra note 3 at 56-57. See also Smith v. United Gypsum Co., supra note 3 at 254.
. Fields v. Volkswagen of America, Inc., supra note 3 at 56 and Smith v. United Gypsum Co., supra note 3 at 254.
. Kirkland v. General Motors Corporation, supra note 3 at 1366; Moss v. Polyco, Inc., 522 P.2d 622, 627 [Okl.1974]; Hogue v. A.B. Chance Co., 592 P.2d 973, 975 [Okl.1979] and McMurray v. Deere and Company, Inc., supra note 5.
The defenses of assumption of risk and contributory negligence, although closely allied, are conceptually distinguishable. While they may arise under the same set of facts and thus sometimes overlap each other, they are founded on separate and distinct principles of law. See Kleppe v. Prawl, 181 Kan. 590, 313 P.2d 227, 230-231 [1957]; White v. McVicker, 216 Iowa 90, 246 N.W. 385, 386 [1933]; Watterlund v. Billings, 112 Vt. 256, 23 A.2d 540, 543 [1942] and Landrum v. Roddy, 143 Neb. 934, 12 N.W.2d 82, 89 [1943]. The latter doctrine is the product of the law of negligence whose source is traceable to Butterfield v. Forrester, 103 Eng.Rep. 926 [K.B.1809]. Assumption of risk, on the other hand, had crystallized much earlier in the form of the maxim volenti non fit injuria, supra note 5, which reflects the Roman law’s notion of legal wrong or injuria. The principle embodied in the maxim is that a loss inflicted by one’s voluntary act or submission is not actionable. Dig. 47, 10, 1, 5 {Quia nulla injuria est, quae in volentem fiat)-, see Burdick, Principles of Roman Law, pg. 504 [1938]. The volenti doctrine is expressed as a common-law rule both in Cruden v. Fentham, 2 Esp. 685, 170 Eng.Rep. 496 [1799] and Priestley v. Fowler, 3 M.& W. 1, 150 Eng.Rep. 1030, 1031-1033 [1837] (a master and servant case where the volenti defense is believed to have received its greatest impetus). See Prosser and Keeton, The Law of Torts, § 68, p. 480 [5th Ed.1984].
Assumption of risk involves voluntary exposure to a known danger and entails both a subjective knowledge and appreciation of the risk involved as well as a voluntary acquiescence. In contrast, contributory negligence is based on an objective standard of conduct which, though it may be inadvertent, falls below the degree of care which would have been exercised by a reasonable person. It often involves the inquiry as to whether the conduct of the plaintiff falls below that of a reasonably prudent man in the protection of himself and is a contributing cause to the injury. It implies the omission of a duty on the part of the injured person and excludes the idea of willfulness. See Walsh v. West Coast Coal Mines, supra note 4, 197 P.2d at 238-239; Detrick v. Garretson Packing Company, 73 Wash.2d 804, 440 P.2d 834, 837 [1968] and Lyons v. Redding Construction Company, supra note 4, 515 P.2d at 822-826.
. See comment n § 402A of the Restatement (Second) of Torts.
. See comment n following § 402A; see also, Shields v. Morton Chemical Company, supra note 5, 518 P.2d at 860, citing to Restatement (Second) of Torts § 402A, comment n at page 356 and McMurray v. Deere and Company, Inc., supra note 5. In Shields, the court noted the universal agreement that contributory negligence in the sense of misuse of the product or of voluntarily and unreasonably proceeding in the *947face of a known danger are good defenses to strict liability. See also Annot., Products Liability: Contributory Negligence or Assumption of Risk as Defense under Doctrine of Strict Liability in Tort, supra note 5 at § 5, p. 253, citing Kirkland v. General Motors, supra note 3, and thirty other jurisdictions for the view that "assumption of risk”, meaning voluntarily and unreasonably proceeding to encounter a known danger, is a defense to an action based upon strict liability in tort.
. Neither Treadway’s familiarity with the tire mounting instructions and warnings nor the adequacy (sufficiency) of the information printed on the label was a disputed issue below.
. See the discussion in the text of the opinion at footnote 23 infra. The recommended jury instruction on assumption of risk that bears No. 9.14 and is found in Chapter 9, Negligence-Comparative Negligence, Uniform Civil Jury Instructions [UCJI 1981], appears to be usable only in trials of negligence-based tort claims. With a slight change in its verbiage, it could be easily adapted for use in products liability cases.
In Smith v. United States Gypsum Co., supra note 3 at 254-255, we refused to hold that an instruction on voluntary assumption of a known defect was required in the trial of that case. There, we found no evidence the defendant knew failure to follow the warnings would make the product more dangerous. That is not the situation in the appeal before us now.
. Gauthier v. AMF, Inc., 788 F.2d 634, 636 [9th Cir.1986].
. See the discussion in the text of the opinion at footnote 23 infra.
Comment j, § 402A of the Restatement (Second) of Torts, states in pertinent part:
” * * * Where warning is given, the seller may reasonably assume that it will be read and heeded; and a product bearing such a warning, which is safe for use if it is followed, is not in defective condition, nor is it unreasonably dangerous.” [Emphasis added.]
. The principle has long been established in Oklahoma that when evidence of an unpleaded defense is admitted without objection, the responsive pleading of the defendant stands amended to conform to the proof. See Nelson v. King, 92 Okl. 5, 217 P. 360, 362 [1923] and Blumenfeld v. Mann, 126 Okl. 64, 258 P. 918 [1927] (syllabus 1). In Blumenfeld the court stated in syllabus 1 that “[t]hough there be a variance between the allegations of an answer and the facts proved on the trial without objection, yet, if it be a case where an amendment of the answer ought to be allowed to conform it to the facts proved, the judgment will not be reversed on account of such variance.” *948See also Liberty Plan Co. v. Francis T. Smith Lumber Co., 360 P.2d 500, 503 [Okl.1961]; Conaway v. Bolt, 174 Okl. 180, 50 P.2d 170, 171 [1935]; Stroup v. Brittain, 105 Okl. 276, 232 P. 814, 815 [1925] and Parsons v. Heenan, 104 Okl. 86, 230 P. 502, 503 [1924]. In Cook v. Sheffield, 181 Okl. 635, 75 P.2d 1101, 1104 [1938], the court said: “The attention of the court must be specifically called to the variance and its prejudicial effect shown ... Unless this is done the party complaining waives the variance, and the pleading will be deemed to have been amended to conform to the proof.” To the same effect is First Nat. Bank v. Cox, 83 Okl. 1, 200 P. 238 [1921] (syllabus 3) and Coats v. Duncan, 202 Okl. 188, 211 P.2d 269, 270 [1949] (syllabus 2). In Coats the court stated the rule that "[w]heré evidence is introduced, without objection, which is inadmissible because not within the issues, on appeal the Supreme Court may consider the pleadings as amended to conform to the proof where the amendment would have been proper at the trial.”
This common-law principle is incorporated in the 1984 Oklahoma Pleading Code, 12 O.S.Supp. 1984 §§ 2001 et seq., where it is codified in § 2015B, which provides:
"AMENDMENTS TO CONFORM TO THE EVIDENCE. When issues not raised by the pleadings or by the pretrial conference order, where the order has superseded the pleadings, are tried by express or implied consent of the parties, they shall be treated in all respects as if they had been raised in the pleadings or the pretrial conference order. Such amendment as may be necessary to cause the pleadings or the pretrial conference order to conform to the evidence and to raise these issues may be made upon motion of any party at any time, even after judgment; but failure so to amend does not affect the result of the trial of these issues. * * *” [Emphasis added.]
.The evidence of a defense that was not plead constitutes "variance." This is so because the proof of such defense "varies ” from the pleaded issues. Evidence of an unpleaded defense, when met with a timely objection, may be excluded. Once "varying" evidence of an unplead defense has been admitted without objection, the answer stands amended, by operation of law, to incorporate that unplead defense and thus make the answer conformable to the elicited proof. Cook v. Sheffield, supra note 15 75 P.2d at 1104; Liberty Plan Co. v. Francis T. Smith Lumber Co., supra note 15 at 503; Conaway v. Bolt, supra note 15 50 P.2d at 171; Stroup v. Brittain, supra note 15 232 P. at 815 and First Nat. Bank v. Cox, supra note 15 200 P. at 241.
Treadway’s disregard of instructions and danger warnings would have been admissible even if an objection to its proffer had been timely interposed on grounds of variance. It clearly was relevant on the issue of the product’s safety.
. Counsel for Uniroyal did seek below a jury charge on the effect of Treadway’s disregard of the warnings and instructions, which would explain the manufacturer’s assertion that the product was not unreasonably dangerous. This charge was requested in the following statement made to the court:
"... [T]he jury should be instructed as the Supreme Court said in Smith v. U.S. Gypsum Case, that when a product has a warning on it when if followed the product is not unreasonably dangerous_” [Emphasis added.]
See also supra note 14 for the text of comment j, Restatement (Second) of Torts.
. Uniroyal’s critical defense was grounded on Treadway’s disregard of known instructions and of appreciated danger. Nowhere in the 15 instructions given by the trial court was that defense explained to the jury. In Instruction 9 the jury was told that if “the Defendant has not proven that Plaintiff was guilty of misuse of the tire as defined herein, then your judgment shall be for the Plaintiff and against the Defendant.” Under the instructions as a whole, Instruction 9 was thus tantamount to a directed verdict for the plaintiff. This is so because the plaintiffs conduct obviously did not fit into "misuse” as that term was defined in Instruction 7, supra note 1.
Whether Uniroyal chose the proper label for the description of its defense — misuse, volenti or simply a denial that the product was dangerous as labeled — the evidence and the requested instructions were quite sufficient to call the trial court’s attention to the essence of Uniroyal’s defense grounded on Treadway’s disregard of instructions and warnings. The trial court has the duty to instruct on its own motion on all the issues and theories of both parties. Its failure to *949instruct on a material or critical defense adduced by the proof constitutes reversible error. The fact that Uniroyal’s defense may have been mischaracterized does not relieve the court of its affirmative responsibility to act in providing the jury with meaningful guidance. See Cunningham v. Charles Pfizer & Co., Inc., 532 P.2d 1377, 1382 [Okl.1975]; Thompson v. Galion Iron Works & Mfg. Co., 201 Okl. 182, 203 P.2d 438, 442 [1949]; Elam v. Beverly, 191 Okl. 375, 129 P.2d 838, 840 [1942] and International Harvester Co. of America v. Snider, 184 Okl. 537, 88 P.2d 606, 610 [1939].
. Acker v. Hopfeld, 416 P.2d 953, 956 [Okl.1966]; McKee v. Neilson, 444 P.2d 194, 199 [Okl.1968]; Croy v. Bacon Transport Co., 604 P.2d 136, 138 [Okl. 1979] and Middlebrook v. Imler, Tenny & Kugler M.D.’s, 713 P.2d 572, 579 [Okl. 1986].
. It is well established in extant case law that the trial court has the duty to instruct the jury properly on decisive issues made by pleadings and evidence introduced at the trial and that failure to do so is reversible error. See First Nat. Bank v. Cox, supra note 15 200 P. at 241; Liberty Nat. Bank of Weatherford v. Semkoff, 184 Okl. 18, 84 P.2d 438, 440 [1938]; Roadway Express v. Baty, 189 Okl. 180, 114 P.2d 935, 938 [1941]; Petty v. Frank, 194 Okl. 382, 151 P.2d 926, 929 [1944] and Peoples Bank of Aurora v. Hoar, 421 P.2d 817, 818 [Okl.1966] (syllabus 3); Rader v. Fleming, 429 P.2d 750, 751 [Okl.1967] (syllabus 1) and McKee v. Neilson, supra note 19 at 195 (syllabus 2). In Haar, supra, the court stated the rule in syllabus 3 that “it is the duty of the court, even though not requested to do so, to cover all material issues and the proper theories of the parties in the instructions to the jury.” In First Nat. Bank v. Cox, supra note 15 200 P. at 241 the court noted that the issue on appeal arose from the evidence and was at variance with the issue joined with the pleadings, but held that it was waived since it was not objected to. The court stated that "fifi is the duty of the court to give, upon his own motion, a substantially correct and proper instruction of the law as is applicable to the facts and issues joined.” [Emphasis mine.]
. See Spencer v. Nelson Sales Co., Inc., 620 P.2d 477, 481 [Okl.App.1980].
. Although Uniroyal did not request an instruction based on Treadway’s disregard of known instructions and of appreciated danger, we still must determine whether it was entitled to one because it was a critical issue in the case. Determining whether a litigant should reap the benefit of a legal theory on appeal even though that legal theory was not presented to the trial court is a difficult determination. The public’s interest in judicial economy supports the proposition that a lawyer must articulate his legal theories to the trial court before relying upon them on appeal. Chaney v. Fields Chevrolet Co., 258 Or. 606, 484 P.2d 824, 827 [1971] (Holman, concurring). The rule against raising new legal theories also prevents unfair surprise to the appellee. Stokes v. Stokes, 143 Ariz. 590, 694 P.2d 1204, 1206 [App.1984]. On the other hand, the public’s interest in seeing that the law is correctly applied in every case supports the idea that, on occasion, an appellate court should consider legal theories for the first time on appeal. Chaney, supra 484 P.2d at 827. The rule against allowing previously untendered theories is procedural and prudential rather than jurisdictional, so exceptions may be made. Where the record contains significant evidence which clearly supports the unarticulated legal theory, no prejudice results to the appellee if the appellate court departs from the rule. Stokes, supra 694 P.2d at 1206. If the admitted evidence is, as here, undisputed, the law’s interest becomes even weightier in favor of allowing review on a theory that applies but was not crisply stated below in the precise verbal garb of accepted terminology.
Uniroyal placed heavy emphasis at trial on Treadway’s failure to heed known warnings and danger. It relied upon these facts in pressing a misuse theory rather than a voluntary-assumption-of-the-risk-of-a-known-defect defense. Little prejudice results to Treadway if this court analyzes these fully litigated and undisputed facts in light of a new legal theory. In this case, public interest in the law’s correct application required that the defendant have the essence of *950its defense explained to the jury in one verbal form or another. For these reasons, I believe it was prejudicial and hence reversible error for the trial court not to incorporate the legal effect of Treadway's conduct in any of its instructions to the jury.
. Hale v. Firestone Tire & Rubber Co., 756 F.2d 1322, 1331 [8th Cir.1985]; Collins v. B.F. Goodrich Co., 558 F.2d 908, 910-912 [8th Cir.1977]; Breazeale v. B.F. Goodrich Co., 564 F.Supp. 1541, 1544 [E.D.La.1983]; see generally cases collected at Anno., Products Liability: Liability for Injury or Death Allegedly Caused by Defective Tire, 81 A.L.R.3d 318, at § 11, pp. 360-363 [1977].
. See cases cited in footnote 23 supra.