This paper looks at the impact of commercial pressures upon common lands. Its main task is to identify the factors that make local possession of the commons vulnerable to involuntary loss in the face of such pressures. As the main location for acquisitions with around 20 million hectares formally acquired since 2007, sub-Saharan Africa is its main focus. After surveying 30 national land laws, it is concluded that there is substantial correlation between those countries that offer the least legal protection to customary land rights and the extent of large-scale leasing. The biggest driver of involuntary loss of commons by rural communities is a matter of law – more specifically, the fact that so many developing country land laws do not deem lands held under community-based norms to amount to real property interests.