This paper presents data that consider ways in which young people experience the curriculum through the lens of subject examination syllabuses (for GCSEs), their associated assessment techniques and structures, and educational policies at national and school level concerning subject choice. Drawing upon an original qualitative dataset from a mixed-methods study of students' views and experiences of GCSE from Northern Ireland (NI) and Wales, the paper explores students' perceptions of choice and fairness in relation to studying various subjects at GCSE. Factors of importance are the subjects available to them through subject option selections at the school level and the ways in which GCSE courses are then administered. In relation to notions of choice and fairness, the paper considers how students see access to the curriculum moderated by national- and school-level decisions regarding the assessment of GCSEs; the extent to which assessment techniques such as tiering, controlled assessment, and modularity, as well as school-level policy decisions about timing of entry to GCSEs (known as early entry) all combine to restrict students' access to the full range of subjects and influence the ways in which they experience these subjects as curricula within their particular school settings.