I make a character, and decide in their backstory they have a childhood sweetheart. That sweetheart is external to the character, but it would be strange for the DM to tell me I have a childhood sweetheart, wouldn't it? What about a hometown? As a player, I could decide that my character's home town was a bit like Mayberry, and that the various people within that town and their relationships with my character shaped them in a variety of ways. That entire town and all the people in it are external to my character, but they are vital to my character's story. Heck, I have a paladin who is married. Actual character I am playing. His wife is definitely external to the character, but her backstory and their relationship is something I feel is under my control. Because having a loving wife is part of my character's story, it is part of my character, even if the wife is an NPC and external to my character.
I'll be honest [MENTION=6801228]Chaosmancer[/MENTION], at this point I consider you to be trolling and not even arguing in good faith. So I see no reason to continue any of the arguments we've been having.
However, I will say that I find this new element of the conversation highly ironic, since if you do believe this, then it is not me that you have an argument with but rather yourself and those that have been arguing similar view points.
Under my theory of play, all you've just said is true. Per the process of play I outlined, I cannot as GM tell you that a backstory relationship regarding a loving wife which was previously established to exist, in fact is false because to do so would be impinging upon the conception of your character. While the NPC wife is external to your character, the nature of the relationship between you and that NPC once established cannot be retconned without your permission because that relationship is part of how your character is defined.
But consider that it is your own side of this argument that disagrees with that. When the "Francis the Guard" example was introduced as a valid process of play, that is to say that the player could introduce an NPC to the setting who was his best friend and insist that that NPC was present right now at this moment in the setting, the claim was made that since the setting/character line was so blurry, the correct and proper response by the GM to the player introducing an NPC to the setting in the middle of an encounter or situation was for the GM to invent that the best friend now held some grudge against the PC on account of some thing that the player had done the past that the GM could now impose on the player. In other words, it was argued that sure, the player can impose things on the setting, but in turn the GM can (and ought) impose facts about the player's character on the player, up to and including changing the fundamental relationship between the PC and NPCs as the player understood them.
How can you not see not only how dysfunctional that is, but how obviously both sides are crossing a not so blurry line, how the ends of this argument actually contradict your claims about it, and how contrived these claims are?
Fundamentally, you cannot introduce a backstory without the GMs permission. You may correctly observe that this means you cannot play a particular character without the GMs permission, and that is true, but even though this is so, this does not mean that the GM can play your character. Typically players create a backstory in good faith, and the GMs validate it as a reasonable backstory and therefore expresses facts that are true within the setting. Occasionally a GM may ask the player to make tweaks to better fit the setting, and the player can either except these tweaks or come up with a different backstory entirely. Very very rarely, a player might introduce a backstory that cannot at all be validated by the GM because it is totally at odds with the setting or else is obviously a bad faith attempt to unfairly hog the spotlight that ought to justly be shared equally by all players, but generally this indicates a problem player, or a player who is completely new to the setting, and isn't something that happens a lot with long running groups. In the case of your otherwise generic and simple background for your Paladin, in most cases I'd expect a GM to validate that, but if the GM was planning to run a game in a setting like Ravenloft or Midnight, he'd be well in his rights to tell you, "In this setting, towns like Mayberry don't really exist. At best, if you insist on playing a character that believes that they are from Mayberry, you have to understand that the character is in some fashion deluded and his beliefs regarding his hometown and the relationships in it are false."
Now, I will say that 30 years ago as a teenage DM I used to think that a GM had no right to tell a player what to play, and I would have probably had to have been convinced that that wasn't true if someone made that claim. But I had in my head at the time a very simplistic idea of character, and I would have been defending a proposition like, "The DM can't force the player to play a LG cleric." and defending a proposition like, "The player should be allowed to make their own character." And while I still might defend those propositions, I now realize that in a healthy game the DM can't approve every character that a player might create. Yes, the DM can and ought to try to accommodate the players wishes regarding his character as far as is possible, but there are some concepts for a character that will sooner or later (and usually sooner) result in dysfunction and a less than enjoyable experience for all parties.
These are muddy waters...
No not really.