Originally Posted by SquareDanceGuy
It depends on the fare. Airlines have an incredible number of different fares. Some fares are valid only for the non-stop, or only for connections in DFW, etc. You'll have to look at the detailed fare rules to see which routings are valid for your particular fare. As a general rule: there is no general rule.
This is very true.
I've been shooed away from connecting through DFW vs. ORD before.