The main objective of this article is to analyse informal learning processes in the field of video games. As many teenagers are engaged in these kinds of practices, the big question is: How do teens learn to play video games? In most cases they do not learn to play video games at school or with their parents, and therefore it is necessary to map and analyse these informal learning strategies (ILS). The aims of this article are to identify the main ILS that teens apply as they acquire and improve their video game literacy, and to develop a series of categories for analysing and classifying these informal learning experiences. After briefly outlining the situation of ILS and teens' transmedia skills, in the context of a general reflection on information literacy (IL) and transmedia literacy (TL), the methodological aspects of research and fieldwork in eight countries is described. A taxonomy of ILS related to video game practices is also presented. The research team identified six modalities of ILS (learning by doing, problem solving, imitation, playing, evaluation and teaching) and expanded them with four main categories (subject, time, space and relationships) that contain a series of oppositions. This set of modalities, categories and oppositions should be considered as a first step in the construction of a set of analytical tools for describing and classifying ILS in the context of teens' video game experiences.