If it helps, here's the RMU rule:
Characters can jump or be thrown from heights, fail a climbing maneuver, or otherwise fall. Roll an attack on the falling character on the Crush table, with an Attack size equal to the falling character’s size and an OB of +1 per foot fallen (reduce the falling distance by the height of the character if they deliberately jumped down). Only magical effects apply to one’s DB; Quickness does not help a falling character. However, characters may use the Acrobatics skill to attempt to control the fall; on a Success, the severity of any resulting critical is reduced by one, and by two on an Absolute Success.
The same is true for Acrobatics in RMSS (it's in the skill description). The bit about size can be ignored for previous editions.