In almost twenty years of playing rpgs, mostly 3.x, I have never needed to worry about party make up or roles, nor optimizing my characters.
However, in this one game I just joined I already have the GM expressing concern about my lack of optimization particularly because I'm the primary arcane caster.
So I'm curious what exactly everyone expects from the various party roles, preferably in more detail than "Tank equals taking all the damage."
I always figured the point of arcane casters in terms of party role was the damage type for getting around DR and the knowledge and spellcraft skills, and perhaps the occasional utility spell such as invisibility or magic item use.
So my character has chill touch and orb of acid for the damage type aspect and has the k arcana, k planes, and spellcraft skills. Then I built the rest of the character as a stealthy deceptive combat caster.
Yes I asked the GM, but I figured I'd also get comments from the community out of curiousity.