The Erasmus+ TeCoLa project (2016-2019) aims to develop and test innovative gamified telecollaboration approaches for secondary schools that address issues of learning diversity in intercultural and Content Integrated Language Learning (CLIL) and teaching. Authentic task-based transnational interactions among peers from different socio-cultural, educational and language backgrounds are at the very heart of the learning process, using telecollaboration as a way to communicate and collaborate. In this paper we will shortly describe the project's foci and will elaborate on the teacher training programme that has been designed on the basis of the teachers' needs and on a sound conceptualisation of telecollaboration tasks that are useful, enjoyable, and meaningful. [For the complete volume, see ED578177.]