Early role-playing games such as "Dungeons & Dragons" assigned random values to a player character's attributes, while allowing each character a fixed number of skills. As a result, characters were at the same time wildly unbalanced in terms of attributes and heavily constrained in terms of skills. "Champions" (1981) introduced a points-based system of purchasing attributes and skills as a means of improving game balance and flexibility. These points are known as character points, and it has become a feature of numerous later games, most notably "GURPS".