*794 Opinion
We consider, and will reject, the contention that the unconstitutionality of the guest statute enunciated by us in
Brown
v.
Merlo
(1973)
Plaintiff, a minor, was injured in an automobile accident in 1969 while riding as a guest in a car driven by defendant John Blackwood and owned by the defendant Escondido Tire Supply Co., Inc. In March 1970 she filed an action for damages, the complaint being framed in Contemplation of the provisions of California’s then existing “guest statute” (Veh. Code, § 17158), which limited recoveiy to death or injuries resulting from intoxication or wilful misconduct. At trial, following plaintiff’s opening statement, the court granted defendants’ motion for nonsuit on the ground that plaintiff’s evidence would not support recoveiy under section 17158. Judgment for defendant was entered pursuant to Code of Civil Procedure section 581c.
Plaintiff appealed contending that the guest statute was unconstitutional and that recovery should be permitted upon a showing of negligence alone. The Court of Appeal rejected this argument and affirmed the trial court’s decision. We denied a hearing in June 1972.
In Februaiy 1973 we held the guest statute unconstitutional as applied to an injured nonowner guest.
(Brown
v.
Merlo, supra,
Plaintiff appeals, contending that the doctrine of res judicata is not applicable. Specifically, she argues (1) that the first judgment is not a bar to the new complaint because the judgment is based upon separate and distinct causes of action; (2) that the trial court should have exercised its discretionary power to reject the defense of res judicata in the interest of *795 justice and fairness; and (3) that defendants are estopped from relying on res judicata in this action because they prevented plaintiff from litigating the issue in the prior proceedings. We conclude that these arguments lack merit, and that the judgment should be affirmed.
A valid final judgment on the merits in favor of a defendant serves as a complete bar to further litigation on the same cause of action.
(Busick
v.
Workmen’s Comp. Appeals Bd
(1972)
Our consideration of plaintiff’s argument involves a significant conceptual matter. It is true that plaintiff has asserted different legal theories in the instant case and in her 1970 complaint. However, the “cause of action” is based upon the harm suffered, as opposed to the particular theory asserted by the litigant.
(Peiser
v.
Mettler
(1958)
Plaintiff, however, points to certain language in
Brown
v.
Merlo, supra,
Assuming that res judicata is available to defendants in the instant matter, plaintiff argues that the trial court, nonetheless, should have exercised its discretionary power to reject the doctrine as a defense. There is some authority for the proposition that, in particular circumstances, courts may refuse to apply res judicata when to do so would constitute a manifest injustice. (See
Greenfield
v.
Mather
(1948)
Previous appellate decisions of this state are in accord. For example, in
Zeppi
v.
State of California
(1962)
In
Bank of America
v.
Department of Mental Hygiene
(1966)
We agree with the positions taken by the Courts of Appeal in
Zeppi
and
Bank of America.
It cannot be denied that judicial or legislative action which results in the overturning of established legal principles often leads to seemingly arbitrary and unwarranted distinctions in the treatment accorded similarly situated parties. However, “[pjublic policy and the interest of litigants alike require that there be an end to litigation.”
(Panos
v.
Great Western Packing Co., supra,
Finally, we reject plaintiff’s argument that defendants, because they moved for a nonsuit in the first action, are now estopped from asserting that judgment as a bar to the instant action. It is true that a very few cases have held that the defendant in a second action is precluded
*798
from asserting res judicata as a defense because of his conduct in prior proceedings. (See
Lunsford
v.
Kosanke
(1956)
The foregoing principle, however, is not applicable to the case before us. Defendants have not attempted to assert inconsistent positions in successive litigations. There has been no conduct on their part which can be characterized as constituting a consent, express or implied, that the issue of their negligence was to be reserved for determination in a second lawsuit. Rather, they have consistently argued that under the substantive law in effect at the time the original complaint was filed, plaintiff had no legal theory upon which recovery for her injuries could be predicated, and that a subsequent change in the law cannot be a basis for reviving a dead claim.
The theories urged by plaintiff would cast doubt on the finality of any judgment dependent upon a then valid substantive defense later held to be unavailable. The general uncertainty induced in our judicial system by such a result cannot be justified by occasional apparent inequities.
We therefore conclude that the order of the trial court sustaining defendants’ demurrer on the grounds of res judicata must be sustained. The judgment is affirmed.
Wright, C. J., McComb, J., Tobriner, J., Mosk, J., Sullivan, J., and Clark, J., concurred.
Appellant’s petition for a rehearing was denied Januaiy 21, 1976.
