Bonus from Blood Rage spell

[Noganov]

Hi everyone! I'm playing a barbarian and today I'm found spell Blood Rage.

Blood Rage:

The targets of this spell become angrier as they fight, the pain of their wounds fueling their strength. An affected creature gains a cumulative +2 morale bonus to Strength and a cumulative -1 penalty to AC for every 5 points of damage it takes (maximum +10 Strength, -5 AC) for the duration of the spell. These bonuses last until the spell expires or the target falls unconscious.

Tell me plz! What kind of bonus does this spell give?
Does it stack with barbarian rage?

[Belafon]

As the spell says, it is a morale bonus. Barbarian Rage is also a morale bonus, so they do not stack. Only the greater applies. Penalties do stack.

Example: a 6th level barbarian rages and a friendly bard casts blood rage on her.

0-4 points of damage - The barbarian has a +4 morale bonus to strength and constitution, +2 morale bonus to will saves, and a -2 penalty to AC.
5-9 points of damage - The barbarian has a +4 morale bonus to strength and constitution, +2 morale bonus to will saves, and a -3 penalty to AC.
10-14 points of damage - The barbarian has a +4 morale bonus to strength and constitution, +2 morale bonus to will saves, and a -4 penalty to AC.
15-19 points of damage - The barbarian has a +6 morale bonus to strength, +4 morale bonus to constitution, +2 morale bonus to will saves, and a -5 penalty to AC.
20-24 points of damage - The barbarian has a +8 morale bonus to strength, +4 morale bonus to constitution, +2 morale bonus to will saves, and a -6 penalty to AC.
25+ points of damage - The barbarian has a +10 morale bonus to strength, +4 morale bonus to constitution, +2 morale bonus to will saves, and a -7 penalty to AC.

[Taja the Barbarian]

It does NOT stack with the Core Rulebook 'chained' Barbarian, since both give a morale bonus to strength: Only the higher strength bonus applies.
It technically does stack with the Pathfinder Unchained Barbarian, which grants a morale bonus to your attack and damage rolls rather than your actual strength.

[Noganov]

Thanks to all of you! =)

[Derklord]

Both Belafon's and Tajas post are incorrect. By this FAQ, you can only be affected by one form of rage; that does include spells.

This is seperate from the normal stacking rules (by which both of their posts would be correct).

[Belafon]

Huh, never noticed that FAQ.

Ugh, there's definitely an argument to be had about whether the blood rage spell gives a "rage effect." (It lacks the language of the rage spell which specifically says it is "otherwise identical with a barbarian's rage," but the spell is blood rage so, you know, it's right there in the name.)

But I really don't feel like I have a useful opinion right now. If anyone else has opinions/citations, please continue.