It depends on the rug which you purchased, why because a few rugs come with built-in rubber backing and a few won’t have. In general, the rug pads provide friction to keep the rug from sliding around when it is placed on any hard or smooth surface. So, the usage of rug pads is for safety to both the rug (prevents damage to its underside) and the user (prevents from slipping). The rug pad will promote proper air circulation to make the rug dry quickly and easily in wet locations.