I'm not sure if I should write this here or in modding forums, I will try here.
I'm near to finish my second install of Baldur's Gate Trilogy not Enhanced with Big World Setup.
In the modules I could choose there is in particular one that catched my attemption: Installing [XP for casting Arcane Spells] [v7.1]
That module allows you to give experience points per spell casted. As rogues get experience from traps (I think that rule is fine because you always get experience even in real life doing things) I think a arcane/divine spellcaster should receive experience points too. I tried to google some alternative system or house rules but I didn't find anything about it so I think in a system I believe is balanced and consist looking for spells arcane/divine progresion table 20 level and adding a bonus on spells according to a main stat of 25.
The result is giving experience as follows:
Level 1 Experience Points: 600
Level 2 Experience Points: 700
Level 3 Experience Points: 800
Level 4 Experience Points: 900
Level 5 Experience Points: 1000
Level 6 Experience Points: 1200
Level 7 Experience Points: 1400
Level 8 Experience Points: 1600
Level 9 Experience Points: 1800
So a wizard with 20 level (not focused in any school) is casting per day around 5-7 9th level spells making a total max of experience points between 9000-12600 experience points per day for that level. In level 20 we talk about millions of experience points so I think I didn't create something very unbalanced unless you see something I'm not able to see rigth now
In level 20 a wizard with no inteligence bonus get this daily spells:
Edited by Kangaax, 21 February 2016 - 10:21 AM.