Русско-англо-русский юридический словарь

obligation; duty. Broadly speaking, the words are synonymous in referring to what a person is required to do or refrain from doing—or for the performance or nonperformance of which the person is responsible. But there are connotative nuances. An obligation is normally an immediate requirement with a specific reference .

A duty may involve legal compulsion and immediacy, but the word carries an overlay of a moral or ethical imperative . More specifically, duty = (1) that which one is required to do or refrain from doing, esp. as occupant of some position, role, or office; or (2) any one of a complex of rights and standards of care imposed by a legal relationship. Sense 2 appears primarily in tort law, in which writers use duty only to mean that there could be liability. (Garner’s Dictionary of Legal Usage)