Post: #2

Unfortunately both skill success change and SKILLGAIN function uses some old weird formulas. I never changed these formulas because some ppl like "old style" servers so I avoid change these old formulas/settings

But anyway, I think the best way to master these skill-related formulas is simply write your own scripted formula on char triggers like @SkillStart or @SkillMakeItem

@SkillStart -> here you can create your own success chance formula, ACTDIFF=-100 means fail and ACTDIFF=100 means success
@SkillMakeItem -> this trigger is called -after- skill success when the crafted item is already created (ACT is the created item), here you can insert your own skillgain formula using SKILLGAIN function

You can also use these formulas directly on skilldef triggers like @Start, @Success, @Fail, etc. Also don't forget to set ADV_RATE=0.0,0.0,0.0 on these skills, this will completely disable the hardcoded skillgain formula to avoid conflicts with your scripted formula