ALTHOUGH FASHIONABLE REFORM HOLDS THAT PROSECUTORIAL DISCRETION IS INHERENTLY ABUSIVE, STUDIES OF THE CALIFORNIA COURTS INDICATE THAT ABUSE OF AUTHORITY IS CONTINGENT UPON THE CONTEXT AND THE MANNER IN WHICH DISCRETION IS EXERCISED. FORMAL RESTRICTIONS ON DISCRETION MIGHT FORCE PROSECUTORS TO RESORT TO CLANDESTINE METHODS OF OPERATION. THE ESTABLISHMENT AND USE OF POLICY ALTERATIONS BY PROSECUTORS, WITHIN FORMAL GUIDELINES, APPEARS UNAVOIDABLE. THE ALTERNATIVE TO NARROWING DISCRETION IS REFORM WHICH BUILDS UPON SOCIAL DYNAMICS THAT SHAPE THE RESPONSIBILITIES AND PROFESSIONAL ASPIRATIONS OF THE PROSECUTORS. RESPONSIBLE EXERCISE OF DISCRETION WITHIN THE ORGANIZATION OF THE CRIMINAL COURTS WAS FOUND IN THE STUDY OF THE CALIFORNIA COURTS. THE MAGISTERIAL MODEL, APPLIED IN THE COURTS OF ALAMEDA COUNTY, USED A STRONG COMMITMENT TO 'REALISTIC' CHARGING OF SUSPECTS AND A PATTERN OF NEGOTIATION THAT RESEMBLED A PROCESS OF INQUIRY. CHARACTERISTICS OF THE ALAMEDA SYSTEM INCLUDE ATTEMPTS TO SETTLE FACTS BEFORE TRIAL, A WILLINGNESS TO TEMPER THE HARSH CRIMINAL CODE, AND A QUICK ASSESSMENT OF A CASE'S NONNEGOTIABILITY. BY CONTRAST, THE ADVERSARIAL SYSTEM USED IN SAN DIEGO INTRODUCED CONSIDERABLE ARBITRARINESS IN CASE OUTCOMES BECAUSE OF THE SYSTEM'S 'TOUGH' CHARGING, PRESUMPTION OF SERIOUSNESS FOR ALL OFFENSES, AND 'COMBATIVE' APPROACH TO BARGAINING. NOTES AND REFERENCES ARE PROVIDED. (TWK)