The creation and development of multimedia devices destined for the general public pose many questions for designers. In this article we present two multimedia applications – a Serious Play and a Serious Game – which were part of an experiment performed in 2006. This article will present both devices designed specifically for the promotion of a prehistoric heritage site – the Gargas caves – and describe how they were received by the general public. The aim of this task was to identify the added value of video play and video game items within the context of everyday use by the general public, and particularly by children.