I've started work on MuFu. The first thing I've done is created several mutant and android sub-races for the player characters to pick. These are some of the "stable" mutant races that have evolved in the post-apocalyptic world. I may create a few more. The players have the option of being a unique mutant (so basically the standard mutant), but I can still use these as antagonists, allies, and NPCs even if nobody wants to be one.
*Suulians (Mutant Human)- Though reptilian in appearance, Suulians are actually descended from human stock. They are short, 3-5 feet tall, and frail, with soft scales ranging from dusky yellow to burnt orange in color. Suulians have small spines that run from the crest of their heads down to their stunted, non-prehensile tails.
Suulians have a =2 to both Strength and Constitution, but gain a +4 bonus to Wisdom.
A deeply spiritual people, Suulians can use cleric and druid spells from the Rule Cyclopedia, functioning as a cleric of equal level in regards to spell advancement. Suulians also have a +2 to save against radiation, and can detect radiation out to 60' by concentrating for one round.
Suulians are not without disadvantages, however. They roll d4s for hit points, due to their frail bones, and they have totally eschewed technology. A Suulian cannot use any technological device, nor may they even roll to identify one. A Suulian can never benefit from a technological device used by another, or risk losing spell ability until they are able to atone.
Suulians have rejected both Law and Chaos, and therefore must be Neutral in alignment. A Suulian who devotes himself to either of the Powers will lose all spell abilities, though no longer has the restrictions regarding technology.
*Nobles (Mutant Humans)
Nobles are emaciated, angular looking humanoids who stand 6-7 feet tall. Their skin is usually bone white, though some take on a sickly bluish hue or an ash gray color. Their hair has the same range of color as their bodies, and their eyes are red and take on a slight gleam in the dark. Nobles have +2 to Dexterity, but -2 to Constitution.
The Nobles once ruled large swaths of Tarraxian in the wake of the apocalypse. They had cowed several semi-stable strains of powerful mutants to serve them, and one particularly powerful Noble had a cadre of heavy artillery military bots to enforce his will. They carved sections of Tarraxian up into fiefdoms, preying on their terrified subjects.
Though the subject is misty, legends say that one Noble turned on his fellows, or perhaps they all fell to infighting. Whatever the cause, their fiefdoms collapsed and their servitors turned on them or deserted. The Nobility were deposed and went underground for several centuries. They have reemerged in recent decades, mostly as vagrants and parasitic scavengers. Some have tried to establish domains again, but the people of Tarraxian remember the old legends.
Nobles have the mutations Vampiric Field, Mesmerism, and a limited form of Regeneration. (They can only regenerate using hit points stolen from Vampiric Field.) Nobles do not need to eat or drink, and are immune to disease and poison. They are effectively immortal; no Noble has been known to die of old age.
Nobles suffer from the defect mutation Albinism. Sunlight causes Nobles to lose 1d4 points of Strength so long as they are exposed to it, as well as the loss of 1d6 hit points per hour. Nobles do not heal naturally; they regenerate only with points stolen from their mutation. Finally, Nobles suffer the same reaction penalties as Androids; the legends of the Nobility live on, and people know about their parasitic need to steal life energy.
*Yrini (Mutated Human)
Yrini are blue-skinned humanoids, about the size and shape of normal humans. Their skin sometimes has tiger stripe patters of dark blue, purple or even red. Their hair and eyes run the spectrum of red-blue-purple. Some of them grow stunted white horns from their foreheads, particularly as they age.
Yrini have +2 to Intelligence and -2 to Dexterity.
Yrini have brains like organic computers, analyzing every course of action, every though, and every new discovery along thousands of lines of thinking. Unfortunately, they are not efficient like actual computers, and thus come off as ponderously slow to other races. Yrini are very interested in the technology and lore of the ancient world. One group on Yrini founded the monastic order known as the Archivists, dedicated to restoring the world to its previous height of civilization.
All Yrini have the mutations Intellectual Affinity: Tinker and Dual Cerebellum. They also have two other randomly determined mental mutations, which cannot be Defects. They do all suffer the Slow Mutant defect, however, due to their inability to act without first considering dozens, if not hundreds, of courses of action. (The Dexterity penalty they suffer is a side effect of this ponderous nature; even in combat, they analyze every possible course of action.)
I have also written up a few models of Android, but I'll post those later.