I liked the idea of working with the greater titans.

at the bottom of this post should be a document that contains all of them (please forgive any errors in the text or stats, I didn’t have enough time to fully proofread the scan. The first section is taken from the 1E Deities and Demigods (D&DG hereafter), and the second section is taken from the 2E Legends and Lore (L&L). We have a number of options on working with these beings. We can take them as a race as a whole as seen in L&L, then give them class levels and individual powers, or we can simply create each one as an individual.
Remember guys, these are
greater titans, so as powerful as the MM titans are, these guys are still their big brothers! I mean geez, look at the hit points! If a 1st-edition monster has more hit points than a 3.5e monster, that’s pretty freakin significant!

I’d say they should have a significant amount of power – perhaps even rivaling the archfiends. Some of them (Kronus, Rhea, and Prometheus in particular) might be rated out too high, and might be better off as gods. But the lesser of them are really just high-level beings that may take worshippers in the same manner as archfiends. And as far as the L&L calling all of them gods… well, don’t forget that Demogorgon, Yeenoghu and others were also rated as gods in 2E and are now back to being “lowly” archfiends in 3E! I’d say the consensus rules on this issue.
As far as what each individual titan should have… all should have DR 15 (at least), all should have a pretty high SR, and all should have spell-like abilities similar to the ones in the MM. They may very well vary in alignment, HD (over 20), ability scores, special attacks and qualities, and possibly other things as well. It also looks like most of them will have a various number of class levels, and we’ll need to figure out how many they actually need, or if we just want to give them the class abilities instead.
One other thing before we get to figuring out what we’re doing. I do remember some of the later Planescape books discussing these greater titans. I think it was Planes of Conflict featuring the titans’ prison on Tarterus, but I could be wrong. It would be great to find this reference to give us some nice insight and background info on the greater titans.
OK, discuss!
