Originally Posted by Fat Lawman
I thought it meant all rock moves, as in rock slide and stuff too
it does. but the ability is mainly for stealth rock.
it gives him an ability like levitate. here lemme give an example..
lets say you have a pokemon weak to rock, tyranitar uses rock move on your pokemon, ohGNOES, you switch in this bug pokemon and his ability makes him immune, preceed to focus blast. did we decide on letting him keep focus blast? but it is a very useful ability