[Daldaen]

http://mboards.eqtraders.com/eq/foru...nker-handout)=

I think the old formula is the classic one.

Old Formula, Pass 1

Pass 1 of the skillup formula is as follows. Note that the chance to pass is a value between 0 and 100.

%-chance to pass = ( (S * 10) / (Y * D) ) / 10.0

D = 1 if the tradeskill attempt was successful at making the primary result, 2 otherwise.
Y = skillup difficulty of the current skill (for tradeskills, this is either 2, 3, or 4 currently). (Kyros note: see below for more on this factor.)



S = Player stat used for this tradeskill. For most skills, it is the higher of your WIS or INT, minus 15. For Smithing, it's the higher of your WIS / INT / STR (no minus 15). For Fletching and Make Poison, it's the higher of your WIS / INT / DEX (no minus 15).

Some items of note about this formula


Higher WIS / INT / Possible tertiary = easier Pass 1 success, up to a point.
Your chance to succeed at Pass 1 is up to twice as good on a successful recipe combine than on a failure.
Certain skills are "harder to skill up in" than others, in that they have a higher chance to succeed at Pass 1 (via a lower Y value), given the same S and D values. (Kyros note: I think Tanker meant "higher" Y values, since the higher Y gets, the harder it is to skill up.)
Old Formula, Pass 2

Pass 2 of the skillup formula was as follows. Note again that the chance to pass is a value between 0 and 100:

%-chance to pass =
For current raw skill <= 15, chance = 100

Otherwise, chance = (200 - K) / 2.0 (note the floating point divide, see glossary)
K = current raw skill, capped at 5 and 190. 5 <= K <= 190 is always true. (Kyros note: Tanker did not include a glossary, but a floating point divide means you keep the decimal part of the result. An integer divide (where you divide by a whole number) discards the decimal part. This also applies to the division in the Pass 1 formula.)

Some items of note about this formula:

Once a player's skill reached 190, the chance to succeed at Pass 2 sat at 5% forever.
From skill = 16 to skill = 190, the chance to succeed at Pass 2 moves linearly from 92% to 5%.

It includes the success/failure modifier in the first pass check.

I’ve found no evidence that this formula is in fact the 2.0 version rather than the 1.0 version.