Let's say your human character has a natural con of 19 but with an item it's 20. Will the HP gain increase according to the increased(in this case 20con) stat when you level? I ask because I may be confusing FL with some other mechanic in some different game where HP gain is not increased even if your con is enhanced by an item.
HP gain and Magical Con enhancement.
Yes.
However, if you get a second magical item, bringing your con to 20(20)^1, you will not get extra hp for the additional 1 above your max.
That's why you hear about all these people putting their con 2 below when starting a character and gathering those two rings of life. That way they can spend their creation points on other stats.
Great, thanks. That's all I wanted to know.