MagicalMaster: I'm applying the conventional wisdom of the of whose forum we're in right now :P
Sure, but we're doing a compare and contrast here. They really are totally different beasts.
dtgreene: It's also worth noting that it differs even between different computer games, even those that are based on the same edition of the game.
Very much so. As someone who has at least dabbled in most of 3E family of games (both PnP and CRPG) I have to be careful to keep the differences straight. A large portion of my screwups on rules are due to forgetting differences from one implementation to another.
MasterZoen: If a Paladin kills someone he genuinely believes is evil because some mastermind has ensured that the person is believed to be evil based upon rational examination of evidence, then the Paladin hasn't actually done anything wrong.
Paladins are responsible for their actions, and you absolutely can fall due to a mistake. Acting in good faith is a mitigating circumstance; you aren't going to fall for arresting someone by mistake and roughed them up in the process, but an extreme transgression like murdering an innocent person isn't going to be covered by a good faith excuse. I'm given to understand that there are quite a few Paladins who fell under such circumstances described in official source material. Bottom line: if you don't personally feel the need to seek atonement after accidentally committing an evil act, then you don't have the ethical disposition of a paladin in the first place.
That's not to say there isn't heated debate on the subject of paladins, the code of conduct, falling, and alignment in general. Those debates can go for hundreds of pages with no resolution, although they can often be interesting reads. I have no interest in going down that rabbit hole here, but from my perspective if the Paladin wants to be the champion of good he claims to be then he must hold himself to a higher standard.
MasterZoen: It just peeved off the DM that my Paladin managed to kill the Big Bad before he finished the ritual to be a Big Bad.
Sounds like the DM just needed to be more adaptable. For instance, your actions could have thrown the city into chaos, loyalists of the old leader would put up wanted posters and seek to try the party for murder, and another villain could step in during the commotion to take the previous one's place.
Another option is just to include occasional NPC's who just plain run-of-the-mill evil every so often. They have no villainous plot and aren't guilty of any particularly heinous crime, and if the Paladin goes after them he's going to make a lot of enemies while chasing red herrings.
dtgreene: What about a paladin who goes around hurting, oppressing, and killing evil entities? Wouldn't that make her evil (and hence ineligible to be a paladin)?
This is one of the angles that has received stronger attention in recent years.
I once saw an interesting discussion of the literary origins of the Paladin and the Orc. Apparently the "savage orc" trope began to appear in literature at about the same time as the "savage brown man" trope was disappearing. The Paladin is the reintroduction of the heroic white man who is morally justified in putting down the savages by violent means. In this sense, the literary forebears that inform the Paladin are completely incompatible with our modern ethical sensibilities, and the more we analyze him the less justified he seems to be. He is dressed in the veneer of heroism and moral superiority, but this facade can crack easily because it's no longer compatible with its own foundation in the eyes of a modern audience.
This isn't to say everyone agrees; we've seen all too well recently that there are far too many people who don't have a problem with open displays of racism (or at very least are willing to turn a blind eye and vote for it). However, a very large portion of the modern audience now finds the classic Paladin deeply unsettling and morally questionable. Some have adapted the Paladin by embracing his lofty ideals; the Paladin really must try to be better than his enemies, stay his hand, and act with compassion. The other approach is to embrace his darker side; the Paladin
is the racist self-righteous evil of our own past, so certain in his own justification that he is oblivious to his own evil. Both are interesting approaches to resolving this fundamental contradiction.