What is the circumstance you are asking about?
"Against it's nature" is purely up to GM fiat and is judged on a case by case basis.
It's interesting; I agree it is GM fiat, but should the player have any input on what is against their nature? They (should) know the character the best, so it seems logical that they would decide, but then you run the risk of them saying everything the caster tries to get them to do is against their nature.
In general, I would rule that if cast on a PC adventurer that attacking a party member is not against its nature. The reason is that adventurers are generally engaging in combat a lot, so attacking things is not contrary to their nature. Running away as far and as fast as they can might very well be against their nature, however, depending on the character's background and personality.
It is up to GM fiat, though.
In general, I would rule that if cast on a PC adventurer that attacking a party member is not against its nature. The reason is that adventurers are generally engaging in combat a lot, so attacking things is not contrary to their nature.
While the latter is true, I don't really think the former follows logically. For example: to a Paladin it would be anathema to betray and attack an ally, even though Paladins are warriors through and through.
But I do agree with the generally voiced sentiment: depends on the situation; ask your GM.
I think that if you cast suggestion to have someone attack a party member then dominate would work as well.
Think about the commands you give a dominated enemy. If you say "attack and kill your companions" then that may run counter to their nature depending on the GM. You could, however, say "defend me to the best of your ability from all attacks" and let the dominated person decide how best to do that. You're liable to get much less resistance from players if you change up your commands.
Many players will argue that attacking companions is against their nature. I would side with you that it may be against their will but is not against their nature (with few exceptions).
Whether attacking one's companions is against one's nature is something that can be determined by past behavior. Has the player given any indication that he distrusts or would consider attacking somebody in his party? If so, the DM can point to that as evidence that attacking a fellow party member is not against his nature. On the other hand, if the character has a code of conduct (such as that of a paladin) with severe consequences for breaking it and he has strictly adhered to it so far, a violation of that code probably would be "against his nature". In any case, if the character would describe the action in question as not merely "wrong" but "unthinkable", it is probably against his nature.
If someone is a fighter or a sellsword, I'd say attacking and killing people is absolutely 100% in their nature. Killing their friends might be against their WILL, but no I would not say a man at arms is acting against his nature killing people who happen to be his friends.
Killing occurs often in the adventuring line of work. So no, despite the fact that it is against your WILL it's not against a characters nature to stick swords in things, if that's what they trained their whole life to do.
If you dominated a LG Paladin and asked him to burn a school house down, then YES that's very much against their nature, because they took oaths and swore to deities and all that.
The bar for me is this: Have you done what you are being ordered to do in the past? If yes, than it's not against your nature to do it again. The fact that people you are killing are your co-workers isn't really an issue (IMHO) unless they are in love or have some deep personal bond. In fact an order like "Stand in the corner until the fight is over" is against a fighters nature more than "stab the people you came here with" is when you really think about it.
It's a level 5 Arcane spell, and there are other "save or die" spells at that level so I think it's power appropriate. It also allows multiple saves depending on wording and GM inclinations so I don't think it's OP to interpret things this way. You can grapple your former ally, you can hold person them and in general have a lot of options to non lethally take care of a dominated PC.
BUT that's just my humble opinion and from the posts I'd say it's probably not a popular one.
As far as I'm concerned if a killer kills. It is their nature to do so.
I use domination or similar effects a lot in my campaigns to create a medium of fair and regulated pvp.
I generally think of "Against nature" and "Against will" as the same thing, and if the two clash "Against will" allways wins.
Being an intelligent creature literally means that we have mastered our nature and enforce our will over it.
Its every creatures nature to survive, sleep, eat and conceive offspring. Even us humans live by that code, in a complex warped manner.
Survival means defending oneself, a character would get no additional save to defend himself, even from allies, but a character ordered not to defend himself from attacks would be due an extra save, because self defence is in his nature.
Feeding means foraging or killing for meat, most intelligent creatures are omnivores, so killing is in our nature only if it means we get to eat the meal. Pointless killing is not in our nature, no matter how trained soldiers we are, nor is it against our nature.
Sleeping is in our nature, but only if we require rest, if a dominated character is ordered to rest then consider how tired the character is to check if he would get an additional save.
Because the intelligent mind has a whole lot to do with what is in our individual nature you should always reason with your players about the things they are made to do when dominated.
If their reasons are too long or vague then dont give the a save, if their reasons are short, to the point and reasonable for their alignment, then they are due one.
Examples:
The player is being made fight his friends.
"They are my only way out of this vampire infested castle"
The reasoning is complex, the players friends are probably the best way out of the castle, but certainly not the only way. No bonus save.
"They are my friends"
Consider how long the group has worked together, has there been any roleplay to back up his friendship claim?
If the characters just met then this is certainly not worth a bonus save.
Sometimes players have "childhood friendship" or "shared locale" backstory to help them work together, such characters would be eligible for the bonus save.
Example that happened in one of my sessions:
A rouge, who had made an ass of himself to his team (bad move, he is still considered an ass despite his best efforts to prove otherwise), gets dominated by a vampire.
I ask said, evil, rouge player:
"So, have anything against attacking your co-workers?"
Reply:
"Hm, no not in particular"
Much later, a Paladin gets dominated by the same re-occurring vampire, the first ally he is made to attack is the rouge, rouge gets a sword to the face, no save.
Next target is the cleric, thankfully the cleric and Paladin are on good terms, and the paladin shakes off the domination.
I would say depending on alignment and personal code attacking allies would be outside most peoples nature. If a dominated person is good aligned and is requested to attack another good aligned character I would say it is out of their nature. Good people don't attack other good people. Now, if a character is evil, it seems pretty clear and easy to say that they will attack good characters, and choatic evil characters would probably attack anybody (for no reason). Lawful evil chracters could make a legimate argument that unless a person has somehow violated the law, or that the law allows them to attack that person for some reason then it would be against their nature, but this is a function of law more than good/evil. I also agree with the earlier statement of nature=will. Overall, the bonus is a plus two, and I think it many cases it will not come up, but the ones where it does will probably be the most important.
Also, just because a character kills does not mean it is in his nature to kill anyone, Paldain for exmaple. However, a good aligned fighter is just as unlikely to kill any good aligned person as the paladin.