This paper introduces a project called iibm (Intelligent Interactions Based on Motion). In this project, we address the question of how to design and develop intelligent software systems controllable by gestures. This work is related to the eld of natural interactions, but we are not only interested in the motion capture issues. We focus on human-computer interaction and we seek to support negotiation of meaning and co-construction of knowledge between the user and the system. The goal is to develop intelligent and adaptive systems easy to use, through gestures, by end users. For that purpose, we exploit the CBR paradigm. CBR enables us to capture users' experiences and to reuse them in order to provide relevant feedback and assistance. This position paper presents the main ideas of our approach and illustrates them with a first experiment made within our test bed environment, with the application iiAnnotate. The paper also discusses the benets and risks of applying our approach to video games.