So that casters don't become even more powerful. When things hit the hour/level mark, they become all day buffs, which is quite convenient because you'll be able to cast them again tomorrow. So when you start having all-day spells they effectively become permanent, except without needing to spend a level 5 spell and several thousand gp casting permanency.
So that casters don't become even more powerful. When things hit the hour/level mark, they become all day buffs, which is quite convenient because you'll be able to cast them again tomorrow. So when you start having all-day spells they effectively become permanent, except without needing to spend a level 5 spell and several thousand gp casting permanency.Yes I follow that but why not Mage Armor and Magic Vestment which are still 1 hour/level? Or have they also been toned down to 1min/level in some errata?
There's no errata. I guess they felt that they were tame enough. Now there are other hour/level buffs but they're allowed because they're typically things that casters wouldn't cast on themselves like greater magic fang and greater magic weapon. I can't really think of others really off the top of my head.
Why are all the "buff" spells mostly 1min/level
Because in 3.0 an 8th level cleric could wake up, buff himself to high heaven, and melee better than the fighter for 8 hours.
with the exception of Mage Armor & Magical Vestments which are 1hour/level?
mage armor allows wizards to live through the first few levels of surprise attacks. Magic vestments is defensive rather than offensive.
I believe the idea is that by the time those buffs become "all day", their value has decreased, because they don't stack with magic armor or bracers of armor.
The magic vestment (and greater magic weapon) are both spells a spell caster is more likely to cast on a party member's equipment than their own, and for an arcane spell caster are unlikely to see much play time from the spell caster directly.
The bonuses are also rather small -- by the time you get the +2 bonus from the spells you are likely to already have +2 equipment of that type. Since the bonuses don't stack or factor for overcoming DR the actual value of the spell is small. Also unlike spells that hit an area or multiple allies the visual impact (and mental impact) of the spells is lessened as well.