Post: #1

how i calculate spell duration time with evaulatin and insc bonus

Post: #2

give all players(npcs)

on=@spelleffect
ARGN3 A multiplier for the spell's duration or effect.

Modify it there.

(Edited, little fail.)

Post: #3

You can edit spell durations under sphere_spell.scp. Find spell that u want to change duration, with on=@effect trigger you can change argn3 <- spell delay like

on=@effect // src <- who cast spell
argn3 += <eval <src.evaluatingintel>/20>

Thats the formula you need.