what dex do? do it increase run speed or what?

and how is the pvp system? is it like...

i hit u.... u hit back.... i kill u.... i no get penalty
i hit u.... u no hit back.... i kill u.... i get penalty

no dex does not increas run speed it increases ur doge rate and range dmg
and about he pvp system check the post about pvp that JonBlaze38 posted