A plough (410; 510) comprising: a frame (512); a ground engaging tool (522a, 530a) that is connected to the frame; and an actuator mechanism (362) that is configured to control a roll angle and / or a pitch angle of the frame (512). The plough also includes a controller (360) that is configured to: receive ground-contour-data (364) that is representative of contours of a field that the plough is to work; and determine an actuator-control-signal (366) for the actuator mechanism (362) based on the ground-contour-data, wherein the actuator-control-signal (366) is for setting the roll angle and / or the pitch angle of the frame (512).