Abstract: A belt retractor (10) is suitable especially for use in an adaptive seat belt system and has a rotatable belt roll (14), a rotary member (18) that can be connected in a torsion-proof manner to the belt roll (14), and an actuator (32; 72) which generates an actuating force and acts upon at least one frictional element (22, 22?) in order to engage said frictional element (22, 22?) with the rotary member (18) that can be connected in a torsion-proof manner to the belt roll (14) so as to decelerate a rotational movement of the belt roll (14). An arrangement for self-reinforcing the actuating force generated by the actuator (32, 72) is disposed between the actuator (32; 72) and the rotary member (18).