From the introduction: Those who are familiar with PHBR10: The Complete Book of Humanoids probably have an idea of what this work is about - adding more races and roleplaying opportunities to your campaign, and in this particular case Darksun campaigns. Some game referees might resent the idea of player character b'rohg and ssurrans running around in their campaigns, and while these humanoid races have obvious advantages in combat, care has been taken to retain game balance at a modest level. Most of the humanoids presented in the following chapter are interesting and challenging roleplaying subjects, but game referees are encouraged to ban certain races if they believe players can and will abuse them. Optional- and house-rules should carefully be taken into consideration before allowing a new PC race.