One consequence of armed conflict, especially that of a non-international character, is serious damage done to vital societal infrastructure. Education–schools and universities–can be severely disrupted, even subject to attack. Targeting of schools may not invariably be unlawful if educational facilities are being put to military use. Such use may itself not be unlawful but it can result in schools being transformed from civilian objects into military objectives–and subject, therefore, to lawful targeting. This was a problem highlighted by humanitarian NGOs a decade ago and led to the formation, by both NGOs and United Nations agencies, of the Global Coalition to Protect Education from Attack (GCPEA). In considering ways of reducing the vulnerability of schools, universities and the students and staff present within them, GCPEA decided to develop a set of "soft law" guidelines on the military use of education, the aim being to assist with Law of Armed Conflict compliance but also to encourage armed forces and armed non-state actors to act well within the limits of the law. The resulting Guidelines were drafted in 2012-13, published in 2013, began being championed by Norway and Argentina in 2014, and were launched at State level within a Safe Schools Declaration in 2015. They have now been endorsed by 106 States and there is evidence now emerging of their positive influence on behavior in conflict zones. The Guidelines are a good example of a successful "soft law" initiative and this paper provides an account of their development and advocacy.