The Efficiency between Luminous armor and Greater Luminous armor

[Masakan]

So let's just think about this for a second if you please. Because I actually have been thinking about this for a while.

Luminous armor gives a +5 AC bonus plus a -4 to all melee attacks effectively making it a +9 to ac
The greater version does the same thing but with a +8 as opposed to a +5 equaling +12
Now imagine the context, if you are getting either of these you are probably going to be getting into the Abjurant champion class ASAP, making luminous armor a +14 and the greater version +17
and you will more then likely already have at the very least a +1 Mithril shirt, which assuming the enchantment bonus counts stacks
but with the abjurant champion bonus to abjuration spells at the end of the class you would still get the +9 and 12 respectively
Making the difference between the 2 a +3 to ac and what is the cost? between a lvl 2 and a lvl 4 spell.

I don't know about Yall, but i can think of a million and 1 better things to do with a level 4 spell slot then a net +3 gain to ac.
I would much rather get the regular version so i can potentially cast it more.

[phaedrusxy]

The enhancement bonus from the armor would not apply to the spell. The enhancement bonus increases the armor bonus of the armor, and armor bonuses do not stack. (Neverwinter Nights got this wrong, if that's where you got the idea.)

I agree that I would just use the level 2 version, unless I was playing at the very high levels of the game where there wasn't that much (relative) difference between the two.

[eggynack]

The standard version is indeed superior, and I say as much in my handbook (noting that to say that this isn't a new observation). But, as phaedrusxy says, you might eventually hit a point when the AC boost is worth more than the spell cost difference, and you may just really care about AC.  I dunno why you'd assume that abjurant champions are the majority of casters of the spell, however. It's probably the best armor spell out there, so most good prepared casters are going to be hitting themselves with it. Maybe not clerics, because they have good armor proficiencies, but druids, normal wizards, and healers, as well as maybe some of the slower casters like adept and ranger make good use of it. Sure, abjurant champions want it more, but it's not like the spell was at all below the threshold of a spell being worthwhile. And, with that in mind, while the greater version might be relatively inefficient, it's not quite as inefficient as you claim most of the time.