Lanefan
Victoria Rules
Once a character's been played for even just a few sessions, it usually becomes fairly obvious what to expect from it to the point where you can almost predict what that character is going to do in amost typical situations. And yes, this includes those characters whose usual modus operandum is "do the unexpected".The problem with “IC-authenticity” as a play virtue is that it’s completely unprovable that anyone actually does it. Any declared action can be held as “true for my conception of my character” and no one can contradict you!
If you can’t demonstrate you’re actually doing it (you can only assert it), it’s pretty useless as a normative goal for play.
This makes it fairly easy to tell when someone's playing a character true* or not.
* - or true enough; characters aren't robots (sorry, all you Warforged fans) and would thus have mood swings just like we do, this represents the "almost" in almost predict.