all or nothing rule
all-or-nothing rule. A gloss on the rule against perpetuities holding that a class gift is invalid in its entirety if it is invalid in part. • The effect is to invalidate a class member’s interest even if it vests within the period of the rule because it may be subject to partial divestment by the remote interest of another class member. [Cases: Perpetuities 4(1). C.J.S. Perpetuities §§ 2, 12, 15–18, 20–24, 27–28, 30, 33, 35–36, 52–53.]