Examination questions need to be sufficiently novel if they are to be effective as measurement instruments. Novelty, however, presupposes creativity, suggesting that question writing is, or should be, a creative process. To explore the boundaries of creativity in question writing, this study made use of two data sources: two corpora of examination questions, and interviews with professional question writers. The study identified various factors that appear to restrict question writers' freedom, exposing a tension between creativity and constraint in question writing. In addition, it illuminated the architecture of examination questions and the mechanisms via which this architecture may affect the predictability of assessment design. The paper argues that, in the context of question writing, constraints are essential as they help to enhance the quality of the assessment. However, when they exceed a certain threshold, they can undermine the purpose that rendered them necessary in the first place.