Devillers, FrédéricDonikian, StéphaneD. Breen and M. Lin2014-01-292014-01-2920031-58113-659-51727-5288https://doi.org/10.2312/SCA03/265-275Behavioural animation techniques provide autonomous characters with the ability to react credibly in interactive simulations. The direction of these autonomous agents is inherently complex. Typically, simulations evolve according to reactive and cognitive behaviours of autonomous agents. The free flow of actions makes it difficult to precisely control the happening of desired events. In this paper, we propose a scenario language designed to support direction of semi-autonomous characters. This language offers temporal management and character communication tools. It also allows parallelism between scenarios, and a form of competition for the reservation of characters. Seen from the computing angle, this language is generic: in other words, it doesn't make assumptions about the nature of the simulation. Lastly, this language allows a programmer to build scenarios in a variety of different styles ranging from highly directed cinema-like scripts to scenarios which will momentary finely tune free streams of actions.