At level 20 you may become a playerkiller. Each time you are killed by another playerkiller you are flagged un-pk. You cannot wimpy from a playerkiller fight, and all astroports are fightable areas. The only safe places on the mud are the guilds.
The players that can kill you are controlled by your pkrange. This range changes over the duration of your PK session but will “start fresh” after are playerkilled by someone and your pk status is removed.
Above all have fun and remember it is just a game.