The Complex Question is the fallacy of treating two separate propositions as a single proposition. Formally, it is the act of asserting the truth of the expression '(A and B) or (not A and not B)'.
The Complex Question is commonly employed by libertarians to argue that liberty necessitates a certain policy. For example, a libertarian may ask "Do you support freedom and the right to bear arms?".
To show the fallacy has occured, argue that the truth or falsity of one of the propositions does not necessitate the truth or falsity of the other. In the above example, we could argue that the right to be safe (from being shot) is more important to freedom than the right to bear arms.
The Complex Question is a special case of The False Dilemma - it assumes both propositions must be true, or both must be false.