Pleas add MU-online PVP openworld system, i think it’s work very well in Diablo 4.
System is:
You can kill everybody and everywhere if you start the fight you get the killer stance for some hours. What mean for example: if you start fight and if you die you have chance to delete your item for 50%. And if you kill the player in fight what you start you get the ‘‘Killer status’’ what mean that you have same chances to lose your item for 24h if other players kill you for 24h and they don’t get killer status from you. Thous % can be more if you kill more pepole and duretion time to.
It is important to understand if player have that killer status other players can kill him and they don’t lose nothing.
2Kill 48h- 75% lose item if die
3Kill 72h - 80% lose item if die
4kill 1week - 100% lose item if die
WIKI muonline:
Mu online from wiki link:
Battle System
The MU Online player versus player (PvP) system allows players to settle their own differences. Playing the hunter or the hunted adds flavor to the game.
Through MU Online’s advanced PK (Player-Killing) system, players can readily engage each other in combat while in specially assigned servers (non-PK servers are also available for new users and for those who do not wish to participate in the PK system). This prevents rampant kill stealing (where players keep following you and killing your enemies to steal exp and items) and lets players settle disputes among themselves.
Press Ctrl + Mouse Click to force attack
It is simple to attack another player. While pressing the CTRL key, click the left mouse button over a character, allowing you to forcibly attack another player.
Self-Defense System
If you are attacked by an enemy without provocation, your character’s self defense becomes activated. A character whose self defense is activated will not be penalized even though he kills the attacker in self-defense. In the event that an attacker wins a battle, the attacker will be penalized.
Chaos Level
This is a built-in retribution system that will punish all players who kill others repeatedly by branding them as killers. These killers in turn will be hunted by other players who wish to become Heroes.
HERO : When you are Hero, your name/color is blue,Rate of item drop is 1%, Exp loss on death is 2% and the hours to become a commoner are 1.
COMMONER : When you are Commoner, your name is Pale Blue, Rate of item drop is
6.25%,Exp loss on death is 4%.
1st STAGE OUTLAW : When you are 1st stage outlaw, your Name / Color is Orange, Rate of item drop is 12.50%, Exp loss on death is 6% and the hours to become a commoner are 3.
2nd STAGE OUTLAW : When you are 2nd stage outlaw, your Name / Color is Red,Rate of item drop is 25%, Exp loss on death is 8% and the hours to become a commoner are 6.
MURDERER : When you are Murderer, your Name / Color is Dark Red,Rate of item drop is 50%, Exp loss on death is 10% and the hours to become a commoner are 9.
Reminder: Item drops will happen regardless of PK level.
Murderer and Hero Status
Everyone starts out with a Commoner status with the player’s name in a pale blue colour. Each Player-Kill (or PK) of a fellow player whose name is in a “blue”, “pale blue” or “orange” colour will increase your murderer/killer status. Your 1st player kill will change the colour of your name to “orange”. The next player kill you commit while your name is coloured “orange” will change the colour to “red”. Then, killing yet another player while your name is coloured “red” will change it to a darker red colour, the 3rd Killer Status. Each player kill you commit after the 3rd killer status will add an additional 3 hours to your time in that status. To shorten your murderer status, you will need to kill monsters. The monster level of each creature you kill while in killer status will subtract an equal number of seconds from your pk timer. If a player with commoner status kills another player with a murderer status in either the 2nd or the 3rd degree, then he/she will gain the Hero status.