What is the test for res judicata?

" 'The doctrine of res judicata precludes parties or their privies from relitigating a cause of action that has been finally determined by a court of competent jurisdiction. Any issue necessarily decided in such litigation is conclusively determined as to the parties or their privies if it is involved in a subsequent lawsuit on a different cause of action.' [Citation.]" (Thibodeau v. Crum (1992) 4 Cal.App.4th 749, 754, 6 Cal.Rptr.2d 27.) " '[T]he rule is that the prior judgment is res judicata on matters which were raised or could have been raised, on matters litigated or litigable.' [Citation.]" (Id. at p. 755, 6 Cal.Rptr.2d 27, original italics.)

"In determining the validity of a plea of res judicata three questions are pertinent: [p] 1. Were the issues decided in the prior adjudication identical with those presented in the later action? [p] 2. Was there a final judgment on the merits? [p] 3. Was the party against whom the plea is asserted a party or in privity with a party to the prior adjudication? [Citations.]" (Stafford v. Yerge (1954) 129 Cal.App.2d 165, 168, 276 P.2d 649.)

"The doctrine of res judicata applies not only to judicial proceedings but also to arbitration proceedings" including, "all matters within the scope of the arbitration, related to the subject matter, and relevant to the issues...." (Thibodeau v. Crum, supra, 4 Cal.App.4th at p. 755, 6 Cal.Rptr.2d 27.)