The “average” illusion (if there is such a thing) remains essentially stationary, and does not react much – if at all – to activities beyond those for which it was initially set up to respond. Let’s say that Chopper sets up a holographic illusion of a door; the basic illusion just sits there, and if someone knocks at it, that person’s hand passes right through.

Several levels of response, however, can be built into the illusion if the mage gathers enough successes (and in some cases, employs the proper Spheres) in order to invoke them:

• A reflexive illusion can respond in a very limited and pre-programmed way. If Chopper’s door resists a visitor’s fist with a wood-like firmness, and offers up a “knocked-on” sound, then the illusion has become reflexive. It still won’t open, but it holds an extra level of realism above the simple illusion.

• At the next level, an interactive illusion can respond to new stimuli in an appropriate way. Perhaps that illusionary door responds with a knocked-on sound, and then swings open to admit the “visitor” to an empty room. As the visitor steps through, the false “room” reveals itself through realistic sensations, interacting with the person who’s encountering that illusion. Obviously, such illusions are correspondingly more difficult than simple ones. And although they appear to react to the presence of their “audience,” they still lack any form of solid existence.

• The highest level – the immersive illusion – performs complex and spontaneous interactivity. Call this one “the Holodeck level” because that’s essentially what it is. Such illusions are as realistic as real life, down to the

ability to cause physical sensations and react to physical activity. Unless such illusions are mental ones, however, the mage who creates them must use a combination of Forces 4 or 5 (to command the complex interplay of energies), Mind 4 (to reinforce the sensations and the sense of belief), and Prime 4 or 5 (to control the enor-mous amounts of energy such a feat demands). Lesser Sphere-Ranks simply cannot craft this level of reality, regardless of the successes involved in the illusion’s creation. And even then, the illusion is still just that: an illusion, not the real thing.