• 1 HExapode, PHysiologie, AssISTance et Objets de Service
• 2 Ethnomining

We are entering a time when sustainable consumption requires a change of lifestyle. Yet behavioural change is not straightforward. To speed up the necessary changes, attention has been paid to human and social sciences as well as technology breakthrough. New interactive devices combining game and persuasive design have emerged and there is a ray of hope that these devices will facilitate societal shift. This article presents the Ecoffices energy challenge, a behaviour change competition for saving energy in office buildings. The challenge was based on a comprehensive use of ICT (sensors, gamified dashboards, etc.) and the study of new eco-friendly behaviors required advanced usage analysis techniques. Though energy savings did occur, they were less important than expected. An analysis of these results pointed out weaknesses related to technical dysfunctions and difficulties in staying engaged in the competition, but a more detailed analysis of the challenge dynamics was necessary. This paper provides such an analysis, using a grid of " ludo-persuasive " principles presented in Negri and Senach (2015) in order to assess both persuasive and gamification properties of the Ecoffices energy challenge.