SAD

Single Ability Dependency is a myth that some classes in Dungeons and Dragons only need one really high stat to be good, and can treat all other stats as their dump stats. For example, in Third Edition, it's assumed that Druids only need wisdom, Wizards only need intelligence, and Bards and Sorcerers only need charisma. It is the opposite of MAD.

In any real game, however, it immediately becomes apparent that all classes require decent scores in multiple abilities. Specifically, any character that treats dexterity or constitution as a dump stat will quickly end up as a coat of red paint along the walls of some dungeon, and classes that you normally think of as depending mostly on dexterity, like rogues and rangers, invariably benefit from a high strength score as well (note that Weapon Finesse in Third Edition only applies to attack rolls, not damage rolls). When using a standard point-buy system, there is not a single class that benefits from sacrificing 3 points of dexterity or constitution in order to raise its god stat from 17 to 18.

With that having been said, some classes definitely depend on fewer ability scores than others. A fighter, for example, only needs high scores in strength and con and a medium score in dex, whereas a paladin needs all of that plus high charisma and wisdom.