Multiverser is adaptable to any character.  It is normally played as an "I" game, and the rules detail the conversion of a real person into a game character; however, a few players have brought in characters from other game systems, and these work just as well.  It would certainly be possible to create an original fictitious Multiverser character just for the game which is not drawn from another source--obviously, nearly all non-player characters are created this way--but no one has done this for a player character as far as I'm aware.  The character has a list of "attributes", ability scores which are more or less innate to the character, and a set of "skills" which represent primarily learned aspects of the character's abilities, although certain abilities which would be considered innate to some types of creature but absent from others would also be skills.

  All skills are divided into four "bias areas", technology, psionics, magic, and body.  Technology is the harnessing of the principles of science, from fire and the wheel through time and inter-dimensional travel.  Psionics is the use of the inner power of the mind, soul, or spirit of a creature.  Magic is power from beyond the universe, from beyond all universes, from a super-natural realm in which gods and other immortal spirit powers are native.  Body is all that can be done by the physical structure of a life form, from basic sentience to non-corporeality.  Although it appears that these four areas may on occasion overlap, the game defines them adequately such that any skill lands in exactly one bias area.

  Each skill has a "bias level" and a "bias intensity"  The bias level is established by the basic principles involved, such as dividing fire from leverage.  The bias intensity is determined by the degree of understanding and difficulty of applications of those principles, such as the difference between extinguishing a fire and keeping one burning underwater.

  In each of the four bias areas, each character has a bias rating, indicating his level of understanding of that bias area.  This is determined by the bias of the skills in that area which he has learned.  The bias level of the character is a factor in his chance to learn new skills and in his chance of success at those he knows.  Each world also is rated in the four bias areas.  This rating defines what is possible within that world, both for the indigenous creatures and for those who come from other worlds (usually versers, but in some worlds visitors of other types).  It also becomes a factor in determining the chance to perform known skills and the chance to learn new ones.

  Because of the use of the combined level-and-intensity ratings, a "bias curve" is set up which defines what is possible in the world such that some things are almost always possible, and other things which seem similar in nature are easily "biased out".  Because the character's chance of success includes not only his own skill rating at a particular skill but also his bias and the world's bias (and an attribute, reflecting his innate ability in that bias area), his chance of success at any skill will change from world to world (in a manner which is simple for the referee to determine), and he will find that in some worlds magic is undependable and technology is strong, while in other worlds his body skills are very potent but his psionics should be avoided.

  There are other modifiers which may influence the success or failure of skill use, especially in combat, but this is the basic model for the game.