In this work, we consider immersive Virtual Reality (VR) as a communication process between humans, mediated by computer systems, which uses interaction, visualization, and other sensory stimuli to convey information. From this viewpoint, it is relevant to understand how VR can solve a given communication problem, what is therefore the expressive power of VR system, i.e., its ability in establishing the communication, what are the guidelines to design an effective system, and what are the more relevant models of VR applications. Firstly, we try to clarify the notion of reality in Virtual Reality systems and conclude that reality is not an intrinsic characteristic of VR, rather the result of a conventional way of coding information. The purpose of coding is to lead the observer to the conclusion that the VR set is what is called in italian as verisimile (from Latin veri similis), i.e., “similar-to-the-real-thing”. So the creation of an effective VR application is an artifice or an illusion. But in order to avoid an over-reliance on the creativity of the VR designer, we intend to identify a solid ground on which different kinds of VR solutions can be considered in terms of their ability to solve the desired communication objective. To this aim, we will rely on methods derived from rhetoric to semiotics.