Heroes in Worlds Without Number are assumed to be human, or close enough as to make no real difference. PCs who want to belong to some more exotic species or demi-human kind can pick the origin Focus appropriate to their chosen species, such as those given in the bestiary chapter for different types of creatures. The availability of these special origins will depend on the campaign and the GM’s permission. Even if elves and dwarves do exist in the campaign world, the GM is not obliged to let players use them as PCs if that choice doesn’t fit the tone or location being used. Note also that a PC who just wants to be different without asking for any special mechanical benefits does not need to buy any special Focus. If their particular demi-human or alien has no real advantages over a human, then they can just proclaim their nature as such, assuming the GM allows such beings in their campaign.