This skill governs the climbing of sheer surface or man-made edifices. The rate of climb is the result of a Deftness Group Effect Die roll multiplied by a factor representing the difficulty of the surface. This factor is at the discretion of the GM. A Critical Failure on the BCS Roll indicates a fall. A normal miss requires another BCS roll, with another failure indicates a fall. A second roll success indicates no progress. When climbing natural formations Climbing Skill is also used. Various pieces of equipment can be used in aiding the BCS roll, increasing the distance climbed or preventing a fall.