An underlying assumption behind a TU game is that agents have a common scale to measure the worth of a coalition. Such a scale may not exist in every situations, which leads to the study of games where the utility is non-transferable (NTU games). We start by introducing a particular type of NTU games called Hedonic games. We chose this type of games for the simplicity of the formalism. Next, we provide the classical definition of a NTU game, which can represent a lot more situations.