viewtopic.php?f=9&t=13007
This is based on the following table:
http://web.archive.org/web/200003080614 ... skills.htm
Which is based on the output of a server-side file:
http://web.archive.org/web/199910011351 ... output.txt
However, we all remember gaining INT from Spirit Speak.
It seems the reason we don't here is because Spirit Speak doesn't use INT to help modify your real (adjusted) skill. But, that would mean that there is no purpose to the "Intelligence 100" in the text file linked above.
My own hypothesis is that stat gain is based on the portion of the skill that is attributed to each stat, regardless of what portion of your real (adjusted) skill it modifies. This would also confirm the following note about starred skills like Spirit Speak on Caswallon's link:
* These Abilities are not influenced by Attributes; they are entirely Skill-based. However, they do provide benefits to associated Attributes through repeated use. See below for the exact Skill to Attribute ratios.