Since Salvia divinorum has qualities of dissociation and psychedelia, people have crafted the SALVIA rating system, in which every subsequent letter is a more intense state of mind within the salvia experience.
"S" stands for subtle; you can definitely tell "something" is happening, but it is difficult to describe what it is. Relaxation and slightly increased libido may be noticed.
"A" stands for altered perceptions; colors and textures enhance, a greater appreciation of music may be felt, depth may grow or shrink, thinking becomes less logical and more playful, etc.
"L" means light visionary state; clear closed-eye visuals (intricate fractals and polychromatic kaleidoscopes) occur. They are almost always two-dimensional. With eyes open, the effects are like that of hypnagogia (a very common condition that occurs right before deep sleep).
"V" stands for vivid visionary state. Complex three-dimensional realistic appearing scenes occur. Sometimes voices may be heard. With eyes open, contact with consensual reality will not be entirely lost, but when you close your eyes you may forget about conscientious reality and enter completely into a dreamlike scene. Shamanistic journeying to other lands--foreign or imaginary; encounters with beings (entities, spirits) or travels to other ages may occur. You may even live the life of another person. At this level you have entered the shaman's world. Or if you prefer: you are in "dream time." With eyes closed, you experience fantasies (dream like happenings with a story line to them). So long as your eyes are closed you may believe they are really occurring.
The "I" stands for immaterial existence. At this level one may no longer be aware of having a body. Consciousness remains and some thought processes are still lucid, but one becomes completely involved in inner experience and looses all contact with consensual reality. Individuality may be lost; one experiences merging with a god/dess, mind, universal consciousness, or bizarre fusions with other objects--real or imagined (e.g. experiences such as merging with a wall or piece of furniture). At this level it is impossible to function in consensual reality, but unfortunately some people do not remain still but move around in this befuddled state. For this reason a sitter is essential to ensure the safety of someone voyaging to these deep levels. To the person experiencing this the phenomenon may be terrifying or exceedingly pleasant; but to an outside observer the individual may appear confused or disoriented.
The final letter stands for the vastly powerful amnesic affects of Salvia. At this stage, either consciousness is lost, or at least one is unable to later recall what one had experienced. The individual may fall, or remain immobile or thrash around; somnambulistic behavior may occur. Injuries can be sustained without pain being felt; on awakening, the individual will have no recollection of what he/she did, experienced, or said during the amnesic state. People cannot recall what they experience in this very deep trance state. This is not a desirable level, because nothing can later be recalled of the experience.