Is Righteous Might intended to have an inherent AC penalty?

[Erbander]

Is Righteous Might intended to give an AC penalty to offset all of the bonuses it grants?

It grants you an AC of 27 when cast at 6th level. A cleric capable of casting a 6th level spell is 11th level. If you are wearing breastplate or chain mail and have a dex of 16 or gained heavy armor proficiency and have a dex of 14 then you would have an AC of 28 (11 + 7 + 10) in mundane armor without a shield. This flat AC would also mean you lose more AC from casting this spell as you go from level 11 though level 14 until you can cast the level 8 version of the spell.

The AC of the level 8 version is one point higher than what someone with mundane armor and no shield could have at level 15.

[Draco18s]

This is a good point and similar to the rational behind the adjustments to the barbarian's dragon form.

(I almost wrote "the dragon's barbarian form" which would be an entirely different game that I would absolutely play)

[Snickersnax]

I was wondered this myself yesterday while perusing the Spell lists looking for good spells. I realized that just about every feature of Righteous Might was worse than the 12th level cleric stats before he cast the spell, but especially AC

[Tholomyes]

I can understand some of the rationale behind these form spells granting static stats, but just it seems like most of them are undertuned, even if you're just looking at the levels you acquire them.