This paper conceptualizes the role of Grand Chambers (GCs), special panels of a greater number of judges often employed by appellate courts sitting in panels. Ever since they were created, GCs and their role within their respective courts have attracted a great deal of attention. Some glorify them as the most important judicial formations, securing the quality of the courts’ decision-making, others vilify them for being too big to be effective or too political. The role of GCs, however, has never been scrutinized as a theoretical concept. This paper aims to develop such conceptualization through distinguishing three components of the GCs’ role: 1) the added value of GC’ view; 2) the way in which that view gets asserted in the court’s decision-making; and 3) the extent to which the court’s decision-making is centralized around the GCs’ view. By doing so, the paper provides tools for more complete and comprehensive accounts of how various GCs influence courts’ decision-making.