with whom CLIFFORD, Justice, joins, dissenting.
I respectfully dissent. Although the Court acknowledges that defendant never raised the section 203(3)(A) partial defense instruction at trial or on appeal, the Court says it must review the trial court’s failure to instruct the jury on a statutory defense “in order to maintain the basic integrity of judicial proceedings” and “to avoid depriving the defendant of his constitutional right to a fundamentally fair trial.” Those imperatives do not apply in this case because the defendant unmistakably waived any instruction on the section 203(3)(A) partial defense. See State v. Boilard, 488 A.2d 1380, 1391 (Me.1985) (holding1 that trial judge does not commit obvious error by not instructing on a defense that was deliberately waived by the defense).
An effective waiver requires sufficient evidence of a voluntary and intentional relinquishment or abandonment of a known right or privilege. Green v. State, 245 A.2d 147, 149 (Me.1968). Such evidence can include acts manifesting a waiver. See State v. Kennedy, 224 Neb. 164, 396 N.W.2d 722, 726 (1986) (“A waiver is the voluntary and intentional relinquishment of a known right, privilege, or claim, and may be demonstrated by or inferred from a person’s conduct.”). See also, Johnson v. Zerbst, 304 U.S. 458, 464, 58 S.Ct. 1019, 1023, 82 L.Ed. 1461 (1938) (“The determination of whether there has been an intelligent waiver ... must depend in each ease, upon the particular facts and circumstances surrounding that ease, including the background, experience and conduct of the accused.”) In the present case the clear, unequivocal acts of the defendant and his counsel in the conduct of his defense demonstrate a waiver.
The omission of the section 203(3)(A) instruction from the court’s charge was consistent with the defendant’s theory of the case. In legal arguments to the judge at the close of the State’s case and again after presentation of all of the evidence, the defendant argued that the State had not proven beyond a reasonable doubt that his speed was in excess of 30 miles over the speed limit and, therefore, that his culpability did not rise to the level of blameworthiness required to convict him of Class A manslaughter. The second motion for judgment of acquittal took place during a chambers conference called to discuss jury instructions.2 After the court *174denied the second motion, defense counsel did not request instruction on the section 203(3)(A) defense. Moreover, after consultation with his client, defense counsel withdrew his request for a special verdict form, stating that the use of the form would “confuse the jury about the issue of what is and isn’t gross negligence.” Although the record does not disclose the nature of the proposed verdict form, given the single charge of manslaughter against the defendant, a verdict form would only have been necessary in this case if the judge had to instruct the jury on the partial defense that would reduce Class A manslaughter to Class B.
Having twice moved for a judgment of acquittal on the Class A manslaughter charge and having been twice denied, the defendant deliberately adopted an all or nothing strategy. Defendant wanted the jury to consider only two possible verdicts: guilty of Class A manslaughter or not guilty. With the ease postured in that way, defendant could use uncertainty over his speed on the motorcycle to argue that the State had not proven reckless or criminally negligent conduct beyond a reasonable doubt, and hence he should be acquitted.3 If the Class B manslaughter instruction were before the jury, and the companion verdict form, uncertainty over the defendant’s speed would only push the jury toward a sure compromise on Class B manslaughter. Thus, the defendant made the tactical decision not to request an instruction on Class B manslaughter. Having been convicted of Class A manslaughter using this tactic, the defendant should not be permitted to now claim that the court erred by failing to give an instruction that the defendant clearly did not want.
Although footnote 2 of the court’s opinion seems to acknowledge the possibility that the defendant could have explicitly waived instruction on the section 203(3)(A) partial defense, the court’s requirement of an explicit waiver goes beyond what the Maine Criminal Code or our decisions require. Title 17-A M.R.S.A. § 101(1) (1983), cited by the Court, does not require that a trial court instruct the jury on all defenses generated by the evidence but waived tactically by the defendant as a ground of defense. Cf. 17-A M.R.S.A. 13-A (1983) (establishing rules governing when a trial court must instruct on lesser included offenses). Section 101(1) was derived from 17-A M.R.S.A. § 5(2) which was repealed by the legislature in 1981. See P.L.1981, ch. 324. Entitled “Pleading and Proof,” former section 5 simply sought to codify fundamental rules concerning the prosecution of a criminal case.4 The comment to 17-A M.R.S.A. § 5 confirms that this was section 5’s limited objective. The comment provides in pertinent part:
This section states several basic rules concerning the prosecution of criminal cases....
*175... If there is evidence of an exception ... subsection 2, paragraph B requires the State to disprove it, contrary to the rule in [State v. Rowe, 238 A.2d 217 (Me.1968)] that the defendant must sustain the burden that he comes within the exception. Subsection 2 also serves to place the burden on the State as to anything ... which the code designates as a “defense.”
L.D. 314 § 5 comment (107th Legis.1975). In abrogating the then prevailing common law rule, section 5(2) shifted the burden of proof from the criminal defendant to the State. It did not preclude a defendant from waiving for tactical reasons an available defense generated by the evidence. Nor did the incorporation of section 5(2)’s mandate into section 101(1) alter the general practices of pleading and proof concerning defenses established by section 5(2). L.D. 811 (110th Legis.1981) (stating that the amended section 101 “sets forth general guidelines for defenses and justifications for criminal conduct” and is “derived from current Title 17-A, section 5”). Therefore, neither section 5(2) nor its statutory successor, section 101(1), embodies a rule requiring the court to instruct on defenses waived by the tactical decisions of the defendant.
Our prior cases also do not support such a rule. In State v. Grover, 460 A.2d 581 (Me.1983), and State v. Giglio, 441 A.2d 303 (Me.1982), the defendants appealed from judgments of conviction, claiming that the trial courts had erred by instructing the juries over the defendants’ objections on a defense raised by the evidence. In holding that it was within the trial court’s discretion to give an unrequested instruction on a factually available defense, we stated that the contested instruction was “not only proper, but necessary.” Giglio, 441 A.2d at 311. See also Grover, 460 A.2d at 584. In those eases, however, we only decided whether the trial court had erred in giving an unrequested instruction to the jury. Thus, at most, Grover and Giglio stand for the proposition that it would not have been error for the trial judge in this case to have instructed the jury on the section 203(3)(A) defense even in the face of the defendant’s tactical decision not to seek such an instruction. If, however, the court reads Grover, Giglio, and section 101(1) to require the trial court to instruct the jury on an available defense despite a waiver of that defense by the defendant’s tactical decisions, the court has substantially altered the obvious error standard in criminal cases.
Obvious errors are “errors or defects affecting substantial rights” that, because of their severity and potential damage to an accused’s ability to receive a fair trial, may be noticed by us absent an objection. M.R.Crim.P. 52(b). Under a proper obvious error analysis, the defendant should not be entitled to relief by reason of his deliberate defensive strategy of withholding a partial defense from the jury’s consideration. There is no manifest injustice when a defendant’s chosen trial strategy fails him. A trial court’s failure to instruct sua sponte on an applicable defense waived by the defendant rises to the level of obvious error only in those limited cases when, on the face of the record, defense counsel’s tactical decision not to raise the defense was so “obviously wrong” and manifestly unreasonable that the trial judge’s accedence to the defendant’s wishes resulted in substantial injustice to the defendant.5 See Boilard, 488 A.2d 1380, 1391 (Me.1985). Cf. State v. Sprague, 617 A.2d 564, 565 (Me.1992) (obvious error to omit instruction on defense that was central to defense case); State v. Davis, 528 A.2d 1267, 1270 (Me.1987) (obvious error to omit instruction where defense was essential to de*176fendant’s case); State v. Daley, 440 A.2d 1058, 1055 (Me.1982) (obvious error to omit an instruction on defense where instruction was crucial to defendant’s receiving a fair trial).
Based on the advice of counsel, defendant chose not to have the jury instructed on the section 203(3)(A) defense. This knowing choice constituted a waiver of the defense. The defendant’s waiver was not so obviously wrong or unreasonable that it required the trial justice to intervene and instruct the jury on the waived defense to preserve the defendant’s right to a fair trial. Id.
I would affirm the judgment.
. While Justice Dufresne, sitting as an Active Retired Justice, wrote the opinion of the Court in State v. Boilard, 488 A.2d 1380 (Me.1985), his discussion of the adequacy of the trial court’s jury instructions failed to gamer the support of any of the other justices. Thus, while the remaining justices concurred with the first four parts of Justice Dufresne’s opinion and with its judgment (which Justice Dufresne entered over his own dissent), they wrote separately and for the court to hold that the trial court's failure to instruct on a defense that the defendant had waived as part of his trial strategy was not obvious error.
. In moving for acquittal at the close of the state’s case, defense counsel argued that the evidence did not support a conviction of class A manslaughter because the state's evidence did not support a finding that defendant’s speed had exceeded the posted forty-five mile speed limit by thirty miles per hour. Defense counsel stated:
Make a motion for judgment of not guilty. Also would ask the court to consider the given testimony to date, that perhaps this is an issue I should have brought up before, the statute talks about a lesser offense, a Class B manslaughter based on a civil violation, and I would suggest to the court that the evidence is such at this point that there is not proof beyond a reasonable doubt. We have had basically speed estimates that have a range of eighty to a hundred miles-an-hour_ If [sic] that reason I would ask for a directed verdict or judgment of acquittal in the case, and further would point to the rule that reduces the charge to Class B in the event there’s a civil violation, which is basically the ground, the foundation for the charge rather than a criminal violation, which is obviously anything over seventy-five would be criminal speeding.
*174The chambers conference began with defense counsel stating that the only special instruction he wanted was a causation instruction. Defense counsel stated:
Based on — first of all I have no request for special instruction other than I think I requested a causation instruction.
... Secondly, I would renew my motion for a verdict at least on the issue between class A and class B based on all the testimony that's in.... Based on ... the state’s best case scenario for their evidence from their reconstruc-tionist it’s 71.65 miles-an-hour, which is under criminal speed. I would suggest even in a light most favorable to the state there is reasonable doubt on the issue.
. Both defense counsel’s opening statement and closing argument resonate with this theme. For example, defense counsel ended his closing argument with the following remarks:
The sole burden of proof again is on the state. They have to prove everything, and the defendant has to prove nothing. I would suggest that given the evidence in this case there is a reasonable doubt as to the actual speed, and whether that was a gross deviation under all the circumstances, and number two, whether in fact the speed that’s alleged in this case or the speed that is even determined by [the expert witness] was causal.
. Former section 5(2)(B) provided:
2. The State is not required to negate any facts expressly designated as a "defense,” or any exception, exclusion, or authorization which is set out in the statute defining the crime, either:
B. By proof at trial, unless the existence of the defense, exception, exclusion or authorization is in issue as a result of evidence admitted at the trial which is sufficient to raise a reasonable doubt on the issue, in which case the State must disprove its existence beyond a reasonable doubt.
17-A M.R.S.A. § 5 (1975) repealed by An Act to Reorganize Certain Chapters of the Maine Criminal Code, P.L.1981, ch. 324.
. State v. Begin, 652 A.2d 102 (Me.1995), may have been such a case. The young victims in that case acknowledged the voluntary consumption of marijuana, furnished by defendants Begin and LaMarche, prior to the alleged sexual acts by Begin. Although Begin denied furnishing marijuana to the boys or engaging in sexual acts with them, he could have asked for a voluntary consumption of drugs instruction, thereby invoking a complete defense to the class B gross sexual assault charges, without abandoning his denial defense to the class C charges of aggravated furnishing of drugs. Indeed, Begin might have been entitled to a judgment of acquittal on the gross sexual assault charges at the completion of the state’s case if he had asked for one on the basis of the voluntary consumption defense. The boys testified to the voluntary consumption of drugs as part of the state's case. There was no contrary evidence until Begin and LaMarche testified in their own defense.