Virtual environments are created by specifying their content, which comprises geometry, interaction, properties, and behavior of the objects. Interaction and behavior can be cumbersome to specify and create, if they have to be implemented through an API. In this paper, we take the script based approach to describing virtual environments. We try to identify a generic and complete, yet simple set of functionality, so that nonprogrammers can readily build their own virtual worlds. We extend the common object behavior paradigm by the notion of an Action-Event-Object triad.