Leal, José PauloPaiva, JoséQueirós, Ricardo2015-12-022015-12-022015978-3-319-27652-6978-3-319-27653-31865-0929http://hdl.handle.net/10400.22/7054Existing gamification services have features that preclude their use by e-learning tools. Odin is a gamification service that mimics the API of state-of-the-art services without these limitations. This paper describes Odin, its role in an e-learning system architecture requiring gamification, and details its implementation. The validation of Odin involved the creation of a small e-learning game, integrated in a Learning Management System (LMS) using the Learning Tools Interoperability (LTI) specification.engGamificationE-learningGame servicesInteroperabilityconference object