feature: experience penalty when killing weaker enemies

Is your feature request related to a problem? Please describe.
This is very good for balancing the UP and farm system in MMORPGs, if a player farms a low level monster he should receive a lower amount of XP, if possible configurable.
As with Ragnarok Online,

Describe the solution you'd like
if you kill a monster with up to 15 levels more than yours, you can earn 50% to 75% more XP, and if you kill monsters with 10 levels less, you will receive a 50% penalty there is 75% XP of monsters.

[WeylonSantana]

@ThousandX I'm sorry to intrude on your feature request, but, why don't you do it for events? It's possible.

[Cheshire92]

Going through events is great and all, but a very user unfriendly way of doing this.

This should be doable, but would need to be configurable properly. (Ie setting the drop-off levels in a config file as well as how much exp is taken away)

[pandinocoder]

Restored issue.

[dhmello]

This was implemented in my game, but I used a metric of up to 15 levels of difference between the player and/or party member, which will gain 0 xp if the difference between the player and the monster is 15 levels or more.