This paper describes a framework for examining the effects of the cognitive complexity of tasks on language production and learner perceptions of task difficulty, and for motivating sequencing decisions in task-based syllabuses. Results of a study of the relationship between task complexity, difficulty, and production show that increasing the cognitive complexity of a direction-giving map task significantly affects speaker-information-giver production (more lexical variety on a complex version and greater fluency on a simple version) and hearer-information-receiver interaction (more confirmation checks on a complex version). Cognitive complexity also significantly affects learner perceptions of difficulty (e.g. a complex version is rated significantly more stressful than a simple version). Task role significantly affects ratings of difficulty, though task sequencing (simple to complex versus the reverse sequence) does not. However, sequencing does affect the accuracy and fluency of speaker production. Implications of the findings for task-based syllabus design and further research into task complexity, difficulty, and production interactions are discussed.