Why are some non-state armed groups more violent than others? Why do some groups resort to inhumane means and methods of war while others restrain from doing so? In trying to answer these questions, a growing number of scholars and practitioners have focused on the drivers of restraint behaviour. However, defining and measuring restraint can be challenging. In this post, Henrique Garbino, Doctoral Candidate at the Swedish Defence University, discusses how we can define and measure restraint focusing on the use of landmines and similar explosive devices by non-state armed groups. This post is based on Henrique’s recent article, “Rebels Against Mines? Legitimacy and Restraint on Landmine Use in the Philippines,” published in Security Studies on 23rd June 2023.