A Game of Thrones: Rivals, territories and resources. What are the intrinsic costs to African lions contained in small, fenced parks? There are about ~20 000 lions in Africa and the general trend is that lions in unfenced parks have decreased, in contrast to southern Africa where fenced parks have contributed to an increase. Lions are important for society and their protection is critical for the species persistence. Some argue that fenced parks are ideal tools for lion conservation because populations are less sensitive to human impacts from adjacent areas compared to unfenced populations. This is likely because fences reduce poaching and human–lion conflict and is a more cost-effective management option. But fencing has significant costs, such as ecosystem fragmentation, loss of dispersal and migration routes, genetic isolation, reduced conservation value of buffer zones, and utilization of fencing materials for wire snare poaching. Both these arguments have merit but focus mostly on extrinsic costs. There is a glaring information gap in considering this argument which is that we are not considering the intrinsic costs to lions when they are contained in fenced parks. Dealing with this information gap is important for the conservation of the lion meta-population as it will establish the importance of the role each type of protection measure (fenced versus open systems) plays in lion conservation. With the use of Bayesian spatially explicit capture-recapture (SECR) models, satellite tracking collars, playback experiments and kinship genetics, we will use predictions based on group territoriality and evolutionary game theory (EGT) to test the effects of being in a small, fenced park on pride behaviour and composition. We will also measure the effect, of what we predict to be a higher-strung social environment, on stress levels of lions. We will compare our data with data from open systems north of South Africa’s borders