You transform your eldritch blast into a barrage of conjured stone and gravel. A rock blast deals magical bludgeoning, piercing, and slashing damage. If you fail to bypass a target's spell resistance with your rock blast, it still deals half damage to that target. Additionally, if the target is not already in an area of difficult terrain, the ground in the target's space is littered with debris and becomes difficult terrain until cleared. If rock blast is combined with an eldritch essence that causes it to affect an area, such as eldritch burst or eldritch cone, all ground in the area that is not already difficult terrain is littered with debris and becomes difficult terrain until cleared.