Group XP Multiplier Formula
 

I have been struggling to enter a value in the rule_values table for Character:GroupExpMultiplier that will match as close as possible to classic Everquest.

My understanding is that for each group member that joins a group, the experience should increase by 2%, for a total of 10% bonus experience if it's a full group.

Assuming I am understanding that correctly, I tried many values in the Character:GroupExpMultiplier field in an attempt to get the bonus as close as possible to 10% with a full group, and you can review my findings below.

I used #npctypespawn 66094 to spawn “a vis ghoul knight” over and over in lower guk for the sake of this test. My character's varied from level 40-47 with a mixture of different races and classes and I grouped them with a full group of 6, then 5, then 4, then 3, 2, and finally solo.

With no group experience modifier, these were the experience values gained per kill of NPC 66094 "a vis ghoul knight":

6 members = 31772 exp
5 members = 38128 exp
4 members = 47659 exp
3 members = 63546 exp
2 members = 95320 exp
1 member = 190642 exp

With a 0.050% group experience modifier, these were the experience values:

6 members = 35204 exp
5 members = 41559 exp
4 members = 51472 exp
3 members = 67994 exp
2 members = 101039 exp
1 member = 190642 exp

This resulted in a difference of:

6 members = 3432 more exp
5 member s= 3431 more exp
4 members = 3813 more exp
3 members = 4448 more exp
2 members = 5719 more exp
1 member = no bonus exp

Now I took the difference and divided it by the original value, then multiplied it by 100 to get the total group exp percentage increase per group member:

6 members = 3432 more exp / 31772 original exp gain X 100 = 10.80% exp gain
5 members = 3431 more exp / 38128 original exp gain X 100 = 8.99% exp gain
4 members = 3813 more exp / 47659 original exp gain X 100 = 8.00% exp gain
3 members = 4448 more exp / 63546 original exp gain X 100 = 6.99% exp gain
2 members = 5719 more exp / 95320 original exp gain X 100 = 5.99% exp gain
1 member = no bonus exp

As you see, this gives me pretty close to 10% for a full group, but it's far from classic because it's not a 2% increase per group member.

Am I just wayyyyyyyyyy off in these calculations? I did not compile the source for my server, so I'm pretty limited to only changing the Character:GroupExpMultiplier value.

Any help is greatly appreciated. Thank you!

Not sure if this helps, but in the source code (zone/exp.cpp)