SAD

Single Ability Dependency is a idea that some classes in Dungeons and Dragons only really depend on a single 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 Sorcerers only need charisma. It is the opposite of MAD.

In practice, almost all SAD classes want to grab at least a 14 in dexterity and constitution, as any character that treats those two as a dump stat will quickly end up as a coat of red paint along the walls of some dungeon, and at least neutral wisdom, as any character that has negative wisdom and doesn't otherwise have a strong will save will kill their friends quicker than a Shin Megami Tensei protagonist going for the neutral ending. SAD is primarily limited to casters, as martial class classes that you normally think of as depending mostly on dexterity, like rogues and rangers, still need an extant 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, only a handful of builds (see next paragraph) will ever benifit from sacrificing 3 points of dexterity or constitution in order to raise its god stat from 17 to 18.

One way to make a class more SAD is to use “X Stat to Y Bonus” material to shift what attribute things depend on. The most iconic example is the Paladin’s Divine Grace, which adds their Charisma to will saves that normally depend on wisdom. This makes Paladin a very attractive dip class to anyone who uses charisma and wants its proficiencies (like a Sorcerer who wants to Gish, a combo famous enough to earn the name sorcadin), but does little good to a pure Paladin since their casting is based on Wisdom (Pathfinder corrects this by making their spells work off charisma, resulting in Paladins everywhere dumping wisdom). Pathfinder’s Oracle can take a revelation to make its AC and reflex save based on its charisma, and take a feat to make its initiative based on charisma as well, rendering only ranged attacks (easily avoided) and some skills (which an Oracle doesn’t typically use) dependent upon dexterity, letting it be the only class in the game that can really survive with a negative dexterity and reduce it to only needing Constitution and Charisma. The extent you can do this really depends on how many resources you want to dump into avoiding an attribute, and how much you’re willing to dive into obscure splat.

With that having been said, some classes definitely depend on fewer ability scores than others. A Wizard, for example, only needs high scores in intelligence and con and a medium score in dex, whereas a Monk needs every single one except charisma to function.