Cov qhov rooj hluav taws yog qhov hluav taws kub uas muaj qee qhov hluav taws kub, xws li cov hluav taws tua hluav taws, cov chaw khiav tawm, cov ncej ntsug, thiab lwm yam. Cov qhov rooj hluav taws yog siv tshwj xeeb los cais cov hluav taws kub hauv kev tsim vaj tsev, thiab ua lub luag haujlwm loj hauv kev tiv thaiv hluav taws. Thaum muaj hluav taws kub, tib neeg tuaj yeem siv qhov rooj hluav taws kom tau txais txoj hauv kev khiav.