Ferocity and regeneration

[partyrico]

If a creature has ferocity and regeneration (in this case an arbiter familiar with battle trance cast on it) does it stay alive forever until the regeneration is defeated?

Regeneration:

Regeneration (Ex) A creature with this ability is difficult to kill. Creatures with regeneration heal damage at a fixed rate, as with fast healing, but they cannot die as long as their regeneration is still functioning (although creatures with regeneration still fall unconscious when their hit points are below 0). Certain attack forms, typically fire and acid, cause a creature's regeneration to stop functioning on the round following the attack. During this round, the creature does not heal any damage and can die normally. The creature's descriptive text describes the types of damage that cause the regeneration to cease functioning.

Attack forms that don't deal hit point damage are not healed by regeneration. Regeneration also does not restore hit points lost from starvation, thirst, or suffocation. Regenerating creatures can regrow lost portions of their bodies and can reattach severed limbs or body parts if they are brought together within 1 hour of severing. Severed parts that are not reattached wither and die normally.

A creature must have a Constitution score to have the regeneration ability.

Ferocity:

Ferocity (Ex) A creature with ferocity remains conscious and can continue fighting even if its hit point total is below 0. The creature is still staggered and loses 1 hit point each round. A creature with ferocity still dies when its hit point total reaches a negative amount equal to its Constitution score.

Battle Trance:

You are transformed into a single-minded force of destruction. You gain the ferocity monster special ability, a number of temporary hit points equal to 1d6 + your caster level (maximum +10), and a +4 morale bonus on saving throws against mind-affecting effects. You cannot use the withdraw action or willingly move away from a creature that has attacked you. When you use this spell, you immediately take 4 points of Intelligence damage. You must make a DC 20 concentration check to cast spells, and all other concentration checks to cast spells have a -5 penalty.

[wraithstrike]

Regen alone keeps you alive until the regeneration is defeated. Ferocity just keeps you fighting until you die.

If you had Regen, but not ferocity you would go unconscious but still be alive as long as you regen is up, and your hit points did equal the total of your negative con score.

Ferocity is written that way because the game can't account for every condition to include regeneration. There is also so no to account for abilities that may be created later.

[partyrico]

That makes sense, would you say that in this case then, the creature would be conscious but staggered and losing health until its health reached a negative amount equal to its Constitution score, after which point it would fall unconscious but continue regenerating?

[wraithstrike]

If the creature is losing 1 hit point but gaining 5 due to regeneration it should not reach the negative con score, but if it does due to an attack, then I think it is fair to say it goes unconscious.

Since these two were not written with the other in mind there probably wont be an official ruling without an FAQ, but that is how I would do it.

[partyrico]

Sounds good, thanks