In lawsuits, relative success depends upon two main factors: the true degree of fault, and the efforts invested on each side. A proposed Litigation Success Function displays this dependence while satisfying other essential properties. Under two different protocols, Nash-Cournot and Stackelberg, solutions are obtained for the litigation efforts, proportionate success, and values of the lawsuit on each side. Outcomes are evaluated in terms of two normative criteria; (i) achieving `justice' (interpreted as equality between Defendant fault and relative Plaintiff success) and (ii) minimizing aggregate litigation cost. Achievement of these aims is determined by the decisiveness of litigation effort relative to true fault.