While trying to adjust the enchanting skill to my preferences, I checked on UESP for the chance formula and found this:

%Chance = Ench + .25*INT + .125*LCK - 2.5*[X]*[enchantment points]
X is 1 for on use and on strikes enchantments, but it is 2 for constant effect.


Then I checked the GMST in the Mod Maker Manuel and CS:

"fEnchantmentChanceMult" 3.0000
"fEnchantmentConstantChanceMult" 0.5000


The ConstantChanceMult I can understand, it basically reduce the chances by half, so I'll just have to raise it a little the reduce the difference of difficulty between normal and constant enchants.

But how does the normal ChanceMult work? Is it like the 2.5 from the formula?

Any help on the matter would be greatly appreciated.

That formula is a little dodgey; I know because I'm partly responsible for it. I published that formula in 2004 as a rough guide to how much fortification would be needed for a specific enchantment. (the 2.5 term is the giveaway) The formula was simplified from a much more complicated "real" formula by reducing the terms assuming the most favorable conditions like having max fatigue, etc. In addition, I'm pretty sure (it's been a long time) that the INT factor is 1/8, not 1/4.
At any rate, the formula is at best an approximation, as it was intended.

I see. Thanks for the precisions.

But the ChanceMult of 3 affects the chances by increasing the difficulty depending on the enchantment points, is that correct?

Yes, and I'm trying to remember how the original formula works... I think it was 7.5x enchant points. That's why the 2.5 in my formula (7.5/3) I'm pretty sure now; it's coming back to me. The CE factor stacks with the normal so it's 7.5/3x0.5 so the 2.5 would become 5 in the quick formula.

So that's how it works! Now I get it.

Thank you so much Fragonard.

Your welcome and happy enchanting.