your spell do 23to 46 fire dmg
you have 20% increased total spell dmg
you have 40% increased total fire dmg
you have 80% increased total cold dmg
you convert 100% fireto colddmg
your spell get converted to cold. now it does 23to 46 cold dmg
the dmg is increased by 20% spell dmg
(23 to 46) * 1,2 = xx
the dmg is increased by 40% fire dmg
(0 to 0) * 1,4 = xx
the dmg is increased by 80% cold dmg
(23 to 46) * 1,8 = xx
23 to 46 is 34,5 average.
20% of 34,5 is 6,9
40% of 0is 0
80% of 34,5 is 27,6
new average dmg is
34,5 +6,9 + 0+ 27,6 = 69
now you get 23% extra as lightning
69* 1,23 = 84,87 average damage
or something like that.
path of building probably explains it better
mine is probably wrong also somewhere
i think its right, the extra dmg added after the other increased damage, thanks a lot