Discretionary Function Law and Legal Definition

Discretionary function is “an action that involves room for policy judgment or the responsibility for deciding the adaptation of means to an end, and discretion in determining how or whether the act shall be done or the course pursued. . . . Insofar as an official action involves both the determination of facts and simple cause-and-effect relationships and also the assessment of costs and benefits, the evaluation of relative effectiveness and risks, and a choice among competing goals and priorities, an official has discretion to the extent that he has been delegated responsibility for the latter kind of value judgment.” Thornton v. City of St. Helens, 425 F.3d 1158, 1168 (9th Cir. Or. 2005)