This goes beyond just failing a speech check.
I'm the kind of player that almost always puts all my points into intelligence, perception, and dialog-based skills when I play RPGs. Because of that, I didn't notice that you can go in the absolute opposite direction with amazing results.
A friend of mine alerted me to the "dumb" dialog options, which show up after you build your character. You don't just not put points in Intelligence. You have to take them away, So instead of getting dialog options that pertain to your Intelligence or Perception, you get stuff like this.
Full story from the WindowsCentral blog...