These words refer to anything that is fitting, proper or called for by legal or ethical standards. Rightful suggests that something is in accordance with some objective set of standards: a rightful heir to the property; the rightful place of women in society. The word is often used when something thought true or fitting has been challenged: protesting that he was still their rightful monarch. Just also emphasizes an objective set of standards by which to judge whether something is fitting, but here the standards, by implication, are legal or moral ones; a just trial; arguing that a just society could not tolerate segregation of any kind.

Due emphasizes appropriateness or reasonableness: promising to answer in due course; a due punishment. In emphasizing moderation and practicality, the word can sometimes seem a denial that objective standards exist and thus imply an arbitrary judgement: asserting that there was no conflict between the censorship law and a due regard for civil liberties. The word can also imply something that has accrued with item or has been left outstanding: public apathy that permits criminals to escape their due punishment.

Deserved and merited both emphasize the earning of something: a deserved honour; a deserved punishment; a merited award. As shown in these examples, deserved can be used both positively and negatively, whereas merited is more often used only for positive achievements. Well-earned is almost synonymous with merited but has greater informality and, if anything, less stress on the actual value of the contribution made: a well-earned rest. Fair is the mildest and most general of these words; it is also the most subjective in suggesting an appeal to reasonableness and open-mindedness: a referee who was scrupulously fair in all his decisions; claiming that it wasn’t fair that he had to do more work than his brother. Equitable , more formal than fair , suggests a solution that is just and reasonable to all parties concerned, but not necessarily wholly satisfactory to all. It is often used in contexts indicating an acceptable compromise rather than those susceptible to sharp distinctions between right and wrong: The wage agreement was equitable to both management and unions, although both had misgivings about certain aspects of the settlement.