SUPPLEMENTAL OPINION ON REHEARING
PER CURIAM.The Attorney General [AG] asks on rehearing that we clarify the retrospective contours of our October 10, 1995 pronouncement, which condemns as unconstitutional the provisions of 40 O.S.1991 §§ 196.1-196.14, the so-called Little Davis-Bacon (or Prevailing Wage) Act. We are urged that the court’s opinion should be given a limited backward reach1 because “hundreds” of laborers’ prevailing-wage claims and “numerous” contracts will be affected by our sentence of nullity. The AG argues that if the declaration of a statute’s invalidity has not been clearly foreshadowed or likely would impose undue hardships, the new rule’s impact might be confined to prospective application. His stated goal for pressing the issue in the postdecisional stage is (a) to prevent “costly litigation” by parties who would doubtless seek to enforce “vested rights” and (b) to avoid any “undeserved windfall” to *32contractors. None of the parties (or amici curiae) has briefed the precise issue now tendered, either below or on appeal. The appellees (Oklahoma City and four of its public trusts) have not challenged the AG’s call for limited retrospectivity of our pronouncement.
A.
The Limits Of Our Sua Sponte Jurisprudence
The AG’s sweeping expectations can be met only insofar as extant jurisprudence will permit.2 A new rule’s prospective effect may be resolved sua sponte when the parties harmed by the condemned law are before the court.3
Because the appellees — qua public construction-site owners subject to prevailing-wage payment (called in this opinion “public builders”) — were adversely affected by the mandatory prevailing-wage clauses and are parties to this litigation, we deem ourselves free to consider sua sponte, at the rehearing stage, what retrospective reach the October 10, 1995 pronouncement ought to be given. The affected public agencies seem entitled to know if they can harvest the fruit of their October 10 victory for their past, current and future construction contracts.
We reject the AG’s quest for our pronouncement’s sweeping prospectivity. That argument raises a host of questions about laborers’ (or about other) claims that are rested on the prevailing-wage rate’s applicability to a given contract in suit. All those claims (which do or would arise out of contracts that stand unaffected by our sentence of nullity in this case) cannot be resolved in this appeal. The issues tendered by them are not before us in an adversary posture. Claimant-laborers are not only strangers to this litigation,4 they are not even included as parties to public-construction contracts. As for the AG’s call for our clarification of those claims, we answer today that nonjurisdictional issues, pressed for the first time on rehearing, are generally deemed unfit for review.5
B.
The Prospective Reach of Our Opinion
The only prospectivity-related issue we may and do decide on rehearing is whether prevailing-wage contract clauses in pre-opinion contracts stand subject to our sentence of nullity.
Because it is clear that our opinion settles a significant first-impression controversy, it should not be given unlimited retroactivity.6 We hence hold that: (a) pub*33lic-constraction contracts negotiated and executed before the date of the opinion shall be impervious to an attack upon the constitutionality of their prevailing-wage clauses; and (b) contracts, like those described in subparagraph (a), though negotiated before but executed after the opinion’s date, shall be equally safe from attack absent proof of a postopinion downward contract price adjustment (that would reflect a pre-execution rejection of the prevailing-wage clause). This notion tracks the general principle that contracts are made in reliance on the law that is in force at the time of their execution.7 Regardless of the date a contract was negotiated and executed, we hold today that the opinion’s declaration of invalidity will govern this case and all other public builders’ constitutional challenges of the prevailing-wage clause’s validity, which stood pending in the litigation pipeline on October 10,1995.8
C.
Claims That May Survive The Opinion’s Sentence Of Nullity Must Await the “Percolation Process”
Because we anticipate a variety of claims and defenses will flow out of public-construction contracts that survive the October 10 sentence of nullity, we express no opinion on their viability until they reach us individually in a posture of lively controversy. Their resolution must await “percolation”9 that will follow in litigation of tomorrow. Issues that undergo an extensive forensic inquiry through the percolation process will provide us with empirical data for fashioning a fair solution that should be considerate of all interests at stake.
SUMMARY
Prevailing-wage clauses in contracts defined by timeline are to be impervious to a constitutional attack. The opinion’s sentence of nullity shall govern this case and all constitutional challenges of the prevailing-wage clause’s validity interposed by public builders, whose claims, counterclaims or cross-claims were pending in the pipeline on October 10,1995. Claims expected to arise out of public-construction contracts that survive this court’s declaration of invalidity must be saved for another day.
WILSON, C.J., and HODGES, LAVENDER, HARGRAVE and OPALA, JJ., concur. KAUGER, V.C.J., and SIMMS, SUMMERS and WATT, JJ., concur in part and dissent in part.. For a discussion of the common-law rule that gives retroactive effect to judicial decisions and of its recognized exceptions, see infra note 6. A fashionable recent genre of prospective application is called the "pipeline doctrine”. The concept embodied in that approach saves from extinction those interests that are presently in litigation (i.e., the case before the court and the cases pending before trial tribunals or in the appellate litigation process) or those capable of being litigated when the new rule is announced. For Oklahoma jurisprudence that applies a new rule of law to cases in the pipeline, see Globe Life Acc. Ins. Co. v. Oklahoma Tax Com’n, Okl., 913 P.2d 1322, 1329 (1996); Schulte v. Oklahoma Tax Com'n, Okl., 882 P.2d 65, 75 (1994); Strelecki v. Oklahoma Tax Com'n, Okl., 872 P.2d 910, 915 n. 44 (1994); Dow Jones & Co. v. State ex rel. Tax Com'n, Okl., 787 P.2d 843, 847 (1990); Schepp v. Hess, Okl., 770 P.2d 34, 39 (1989); Beauchamp v. Southwestern Nat. Ins. Co., Okl., 746 P.2d 673, 676-677 (1987); A.E. v. State, Okl., 743 P.2d 1041, 1044 (1987); Amoco Production v. Corp. Com’n of Okl., Okl.App., 751 P.2d 203, 208 (1986); Mann v. State Farm Mut. Auto. Ins. Co., Okl., 698 P.2d 925, 929 (1985); Unah v. Martin, Okl., 676 P.2d 1366, 1370 (1984); Snethen v. Oklahoma State Union of the Farmers Educational & Cooperative Union of America, Okl., 664 P.2d 377, 382 (1983). James B. Beam Distilling Co. v. Georgia, 501 U.S. 529, 536-537, 111 S.Ct. 2439, 2444-2445, 115 L.Ed.2d 481 (1991), is a U.S. Supreme Court refinement of the pipeline doctrine aimed at securing equality for all pending claims (or for those capable of being litigated) when the new rule is announced. See also Harper v. Virginia Dept. of Taxation, 509 U.S. 86, 97-98, 113 S.Ct. 2510, 2518, 125 L.Ed.2d 74 (1993).
. For Oklahoma jurisprudence limiting sua sponte a new rule of law to pipeline cases, see Globe Life, supra note 1 at 1329; Schulte, supra note 1 at 73 n. 30; Amoco, supra note 1 at 208; Schepp, supra note 1 at 39; Dow Jones, supra note 1 at 847; Snethen, supra note 1 at 382; Beauchamp, supra note 1 at 676-677; A.E., supra note 1 at 1044; Mann, supra note 1 at 929; Uriah, supra note 1 at 1370.
. See, e.g., the cases cited in supra note 2.
. The Oklahoma State Building and Construction Trades Council (representing laborers’ interests) was granted leave to tile an amicus curiae brief in this case. Amici curiae cannot expand the contours of a litigated controversy; their participation must stand confined to issues raised in the trial tribunal and preserved for review. Gettler v. Cities Service Co., Okl., 739 P.2d 515, 518 (1987); Teleco, Inc. v. Corporation Commission, Okl., 649 P.2d 772, 774 (1982).
. See Brigance v. Velvet Dove Restaurant, Okl., 756 P.2d 1232, 1234 (1988); Pirrong v. Pirrong, Okl., 552 P.2d 383, 387 (1976); Pointer v. Hill, Okl., 536 P.2d 358, 361 (1975); Brown v. State Election Bd., Okl., 369 P.2d 140, 151 (1962); Hope v. Peck, 38 Okl. 531, 134 P. 33 (1913). For similar federal jurisprudence, see Wills v. Texas, - U.S. -, 114 S.Ct. 1867, 128 L.Ed.2d 488 (1994) (O'Connor, J., concurring); Hoover v. Ronwin, 466 U.S. 558, 574 n. 25, 104 S.Ct 1989, 1998 n. 25, 80 L.Ed.2d 590 (1984); Radio Station WOW v. Johnson, 326 U.S. 120, 128, 65 S.Ct. 1475, 1480, 89 L.Ed. 2092 (1945).
.The rule of limited retroactivity is an exception carved out of the common-law rule of general retroactivity (the latter rule gives retroactive effect to judicial decisions). U.S. Supreme Court jurisprudence has long recognized that the rule of general retroactivity applies to constitutional decisions. Harper, supra note 1, 509 U.S. at 97-98, 113 S.Ct. at 2518 (citing Robinson v. Neil, 409 U.S. 505, 507, 93 S.Ct. 876, 877, 35 L.Ed.2d 29 (1973), and Kuhn v. Fairmont Coal Co., 215 U.S. 349, 372, 30 S.Ct. 140, 148, 54 L.Ed. 228 (1910) (Holmes, J., dissenting)); see also Strelecki, supra note 1 at 914 n. 30. Retroactive *33operation of an overruling decision is neither required nor prohibited by the U.S. Constitution. Judicial policy determines whether, and to what extent, a new rule will operate retroactively. Griggs v. State ex rel. Oklahoma Dept. of Transp., Okl., 702 P.2d 1017, 1020 (1985). In Great Northern Railway v. Sunburst Oil & Refining Co., 287 U.S. 358, 364, 53 S.Ct. 145, 148, 77 L.Ed. 360 (1932), a noncriminal case resolving no question of constitutional dimension, the Court held that a state may choose for itself — free from federal constitutional fetters — between the principle of relation back and forward operation of its precedents.
.Sunray DX Oil Company v. Cole, Okl., 461 P.2d 305, 309 (1969); Landowners, Oil, Gas & Roy. Own. v. Corporation Com’n, Okl., 420 P.2d 542, 544 (1966); Oklahoma Nat. Gas Co. v. Long, Okl., 406 P.2d 499, 502 (1965).
. For a discussion of the "pipeline doctrine", see supra note 1.
. Percolation is "the independent evaluation of a legal issue by different courts,” which “allows a period of exploratory consideration” before the highest appellate court ends the process with a binding rule. John E. Sexton, A Managerial Theory Of The Supreme Court Responsibilities: An Empirical Study, 59 N.Y.U.L.Rev. 681 (1984); Todd J. Tiberi, Comment, Supreme Court Denials of Certiorari in Conflicts Cases: Percolation or Procrastination?, 54 U.Pitt.L.Rev. 861 (1993).