Quote Originally Posted by patchyman View Post
I have definitely seen “Lawful Good” characters (including paladins) act in abhorrent ways to combat Evil.

Specifically, I have seen a Paladin slit the throat of an unarmed prisoner of war, he believed was Evil, against the objections of every member of the party, including the Chaotic Neutral Rogue. Note that the alternative in that case (proposed by my Neutral Good Fighter), was single honourable combat to the death against my Fighter. (If the orc won, he would go free).

The Paladin’s player subscribed to the ethos that you are responsible for any Evil you do not prevent. If through your action (or inaction) an Evil person goes free, you are responsible for the Evil done because you did not stop them.

These were all played by mature adults and experienced role players.

Also, it turned out that orcs were not always evil in this setting, and that particular orc was fighting back against people destroying his home.
At some point you need a DM to actually uphold the rules of the game. This is no less true for alignment than it is for anything else that requires a modicum of judgment.