This report examines how training in IHL and related norms of restraint (collectively labelled as “IHL norms” in this report) can shape combatant attitudes and, ultimately, military conduct. The findings presented here show that efforts to promote IHL norms among combatants – through training and other means of norm socialization – can shift combatant attitudes and generate measurable effects in increasing adherence to IHL. However, the survey results also provide greater context for improving the success of training in IHL, notably highlighting the countervailing influence of force protection and military advantage values that also shape combatant attitudes towards restraint. Such evidence is vital for understanding whether – and how – IHL and related norms can improve protection outcomes for civilians in war.