I like to have my character pretty firmly in mind by level 3 from a role-playing perspective. Before about level 3 or so I still feel free to change my character's voice, mannerisms, personality, etc. because what I had planned on character creation doesn't always feel right as I actually start...
I agree with the consensus here. Lies need to be intentional falsehoods, not just untrue statements. I [I]especially[I] agree with the poster who said that detecting untrue statements would basically be a 20 questions line to absolute truth and would be extremely over powered.
On the other...