Con

[Synfain]

Does con directly affect hp gained on lev and if so by me running wind stance am I hurting myself for hp each lev or is it based off of base con?

Does enhanced con factor at all into hp gained per lev?

[Seventh]

Con does affect HP per level; one extra hit point per level per point of Con bonus. However any HP you lose due to running windstance are given back once you turn it off; being in windstance while leveling up will not permanently ding your HP. Vice Versa with Con increases.

[kernal42]

Con changes are retroactive, so you are not ruining your build by running in wind-stance.

-Kernal

[hu-flung-pu]

It goes off of your base CON. You can't level up with bears endurance for extra hit points or fox's cunning for skills.

[Gorbadoc]

It goes off of your base CON. You can't level up with bears endurance for extra hit points or fox's cunning for skills.

This is poorly-worded. If you level up with Bear's Endurance, you will have the extra hit points-- right up until Bear's Endurance wears off.

Like the first two responses said, temporary changes to your constitution don't affect you in the long-term. At any given time, your current constitution (with items, stances, etc) is used to calculate a bonus (or penalty) to your current hitpoints.

[dkyle]

It goes off of your base CON. You can't level up with bears endurance for extra hit points or fox's cunning for skills.

True for Fox's Cunning, false for Bears' Endurance. Extra CON from spells and items most certainly do add HP.

Spells and item do not apply for the purposes of taking feats and enhancements, for example the Earth Stance/Strike line. That's Base+Tomes only. The penalty from Wind Stance also does not apply, so 18 Base+Tome Con is enough for Earth IV, whether or not you're in Wind Stance or not.