The Dink Network

Try using move_stop() instead of move(). That way the hardness will only update after the rock has moved. With move(), it updates at the same time as the rock starts to move, so it will be at the very same spot. If you use move_stop(), though, you'd also probably want to freeze Dink or take some other cautionary measure so that it's not possible for the player to interrupt the script and duck the rock up, figuratively speaking.

Is &location a global variable? I don't think what you are trying to do would work with a local.