To what degree is complex language driven by personal cognitive factors versus strategic self-presentation? Studies teasing apart these two influences on complexity are hard to design and evidence bearing on the question is not abundant. To fill this gap, the present studies explored two models relevant to a form of communication full of strategic implications: deception. The cognitive strain model suggests that because lies are cognitively draining, deception will generally reduce complexity, whereas the strategic model expects the liar to adjust complexity up or down depending on the perceived benefits. Three studies tested differential predictions from these models by scoring different forms of linguistic complexity (dialectical and elaborative) for deceptive communications in real-world and experimental contexts. Results from these studies support the value of a strategic model of the effect of lying on complex language, thus suggesting that people strategically manipulate the complexity of their language to accomplish specific goals.