Conceptual replications have received increased coverage in the educational research agenda. This article argues for clarity in, and justification of, the definition, scope, and boundaries of a conceptual replication and what it can and cannot do. It argues for clear justifications when changing components from those of the original study. The article raises issues concerning internal validity and construct validity which arise from the elision of replication with applicability and generalisability in a conceptual replication, and questions how far the "concept" needs, and can obtain, greater separation from context. It indicates limits to the power of conceptual replications to falsify and verify the original study, and argues for greater specificity, precision, accuracy, and attention to contexts, conditions, and causality and their influence on outcomes. Implications are drawn for preparing, planning, conducting, analysing, judging, and reporting "fair" conceptual replications in education, identifying 10 "rules" for a fair conceptual replication.