In the D&D universe, Good and Evil are clearly cut, defined, and enforced. There isn't any gray area in D&D, in terms of morality/philosophical ramifications, nor should their be. There is no need to justify any act. It is Good, Evil, Lawful, Chaotic, or Neutral, or a combination of Law/Chaos/Neutrality and Good/Evil/Neutrality. It is never Good AND Evil, it is never Lawful AND Chaotic.
To the Good people of the D&D universe, Trolls have no rights. They eat children, they steal sheep, they ambush the helpless. They are the equivalent of venomous spiders in the real world. You stomp them to death and hope you don't get bitten when you do it.
You don't pull it's legs off (the spider equivalent of beating a troll into unconciousness) and then ask if it's going to bite you or not.
It is never Evil to kill any one of the "usually" or "always" Evil beings. One of the core tenants of the D&D universe is the battle between Good and Evil.
Could you imagine Aragorn beating an Uruk-hai into submission and then asking it nicely if it was there to kill him?
No.
Aggressive Predator - Tiggers
Opps, I was a little too tigger happy with my keyboard.*Snort*
T-I-Double Guh-ER.
Sorry had to do it. Interesting on the Alignment though.
Kill the Duergar. Didn't have a second thought about it.
to ThatDarnDM: The 3.x D&D Universe is the one outlined in the core books (DMG and PH). It clearly defines all of the alignments and there are no gray areas. Yes, it is not an all inclusive system, and yes, it has problems, but it is very clear in it's definitions. Disregarding that system and implementing your own (should you be the DM) is absolutely fine, but for the purposes of this thread, because the OP did not mention that he was homebrewing alignments, we have to assume he's using the 3.x D&D Universe's system.
To those saying Aragorn would not kill an Uruk-hai: He killed many. Yes, they were in an opposing army, and yes, they were all trying to kill him. However, some did not directly attack him or his allies before he dispatched them. He struck first on many occasions, because he knew that Uruk-hai were evil; minions of Saruman. That he did not give each Uruk-hai the chance to throw it's weapon down and surrender even once is paramount proof to that.
When an Orc joined combat while Aragorn was already fighting, he dispatched the Orc. He didn't ask to make sure it was his enemy. Can you imagine that? In the middle of a battle field, in a very british manner, "Pardon old chap, I don't mean to be rude but I say, do you happen to be of the opinion that you might want to kill me?"
Let it be known that I am amoral myself, and all I have to go by are the very definitions that have been set by the 3.x universe.
To those saying Aragorn would not kill an Uruk-hai: He killed many. Yes, they were in an opposing army, and yes, they were all trying to kill him. However, some did not directly attack him or his allies before he dispatched them. He struck first on many occasions, because he knew that Uruk-hai were evil; minions of Saruman. That he did not give each Uruk-hai the chance to throw it's weapon down and surrender even once is paramount proof to that.
When an Orc joined combat while Aragorn was already fighting, he dispatched the Orc. He didn't ask to make sure it was his enemy. Can you imagine that? In the middle of a battle field, in a very british manner, "Pardon old chap, I don't mean to be rude but I say, do you happen to be of the opinion that you might want to kill me?"

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.