Before this becomes the inevitable flame-a-palooza about the Tormite dogma, let me reign it back in the direction of the original post. Yeah, the 'static' alignment phenomenon is strange. It prevents people from converting others. It prevents evil characters from -ever- becoming good, or good characters from -ever- becoming evil, despite possible overwhelming situations, or the setting being absolutely tipped in one way or the other.
But then, do actions determine alignment, or does intent? Is a character evil because they have an evil approach to life, or because they have done evil things in the past? Can a character be born evil?
Here's my take on it: It's been said time and again, Evil is a real, actual force in the Realms, much like Good is, too, and even neutrality. There are creatures that are -inherently- evil. Born evil. Undoubtedly evil. Unmitigatingly evil. Well, you get the idea. Of course, there'll be the 1-in-a-million outliers, but we can't judge by the exception. But I digress! What I'm trying to say here, is that you don't need to have done something evil to be evil. You need only be of evil intent. A ten-year-old in the realms who has never done anything remotely life-altering in his existence, and is suddenly confronted with the chance to steal a dying man's purse of coins and then slit his throat with little or no consequence, and -does- that, is evil. He had it in him before the act, however. The act itself proves that he is of evil disposition, but it's the intent, the idea, the -wish- to do it that makes him evil.
Where does this leave us in the static vs. dynamic debate? Well! Quite simple. If you wish a character to convert, to change their alignment, don't look at the actions, look at the intent. If you do this, it'll be impossible, from a roleplay standpoint, for the other character to refuse your advances and efforts, unless there is a very, very good reason for the character to stick with his alignment (and this can be anything from an evil character secretely pretending to be a pious convertee to a fallen Paladin pretending to learn the ways of the evil thieves' guild so that he can smite them all later on and regain his holiness).
To give an example: Character A murders Character B. Character C, a Priest of Ilmater, after a long series of meetings and scenes finally manages to pry it out of Character A the truth about Character B's death. The appropriate approach here isn't, "Don't murder anymore people, for this is evil." The approach is, "Why did you murder him? What was your intention behind it? Was it for gold, for glory, for power?" In understanding the motivations of another character, you can much more effectively change their alignment. I'm a big fan of PC-influenced alignment change. Surely, DM plots and the like can also influence your character greatly, but it's in player interaction that I think the answer to this should lie. There is simply no sense in saying, "Well, my Paladin sold his soul to a devil because he caught a glimpse of the power he could have had, and so fell from grace, but he would have never fallen from grace for questing daily and befrieding the local gang of thugs". One is much huger and bizarre and unique than the other (as all most DM interventions when compared with player initiatives, for obvious reasons), but the second way is just as effective.
If you ask me whether a character should have immobile, static alignment? Well, telling yourself that it is impossible to change your character's alignment is a bit silly, but going back to the point I made about Good and Evil actually existing in FR, we must remember that in FR, too, there are people willing to sacrifice themselves to many, many causes on both sides. If you offer a character the final choice between death and conversion, it depends on the player, rather than the character, to make the decision. Maybe they don't want to play a fallen Paladin. Maybe they think that if the character died, they'd better achieve what they were trying to do with him in the first place, which, say, could be, "Play a Paladin that doesn't give up" or, "Play a fanatical cultist of Cyric".
In the end of the day, it all boils down to the choices of the players, and the rulings of DMs. But letting your character be changed by the environment never hurts. It only enriches the experience and makes them much more interesting to play with. When a character draws a long and interesting arc in the story of a PW server like this, they are remembered for it.
- Kiaring