How'd we go from discussing RAW and the spirit of the rules to you insulting me and mounting your 9 hand horse?
I am not specifically targeting you in my reply, and sincerely apologize if I have inadvertently offended you. However, there seems to be an interesting trend around here where posters apparently attempt to use "common sense" and "obviously intended to do XXX" to justify passing off their own houserules as RAW.
I can't and won't dictate how you would run your games, nor do I really care (simply because they are not my games), but I feel that however meaningful or reasonable a proposed alternate interpretation of the rules may be, it is ultimately a houserule, and ought to be recognized as such.
To me, the manner in which a thread such as this could be answered is actually very simple and straighforward. The OP asked if a dragonborn fighter could mark using his breath weapon. I feel the best solution would simply be to point out how the rules on combat challenge evidently support the PC being able to perform such a feat. However, the respondent could also go one step further by offering his own opinions on whether he feels that it is a good idea or not, as well as explaining why he feels it to be so, as well as any proposed solutions.
At the end of the day, how the OP wishes to run his game should entirely be up to him. All we can (and should, IMO) do is to simply allow him to make an informed decision, so that he knows what to expect and what he will be getting into by choosing to run/interpret the rules in a certain manner. RAW seems fairly clear-cut in this case. Intent less so.
You did fulfil the first 2 criteria by explaining why you felt that combat challenge ought not to apply to ranged AoE effects like dragon breath or scorching burst. However, I felt that you also came across as being too bossy and arrogant by essentially implying that your take was the "only right one there can be" and that any other interpretations contrary to yours automatically mean that the people behind them are somehow devoid of any common sense whatsoever.
In short, I see it as a form of personal attack, because what I perceive you as saying is in effect "You obviously lack common sense if you disagree with me". I agree that your take is one possible interpretation, but I do not agree that it is the only plausible one. Especially since I still stand by my own original explanation, and this incidentally, also stems from my own belief on how I feel combat challenge was intended to work (that yes, you can mark at range), and not simply because I enjoy being difficult or arguing with other posters for the sake of arguing.
