Since Brett’s essays on how he created the world of Flat Black have been well received, I thought it possible some of you might like to read about how I developed Tela, the setting of my current historical fantasy campaign. Here is how I went about creating seven humanoid sapient races.
To start with, I had each fantasy race be native to one or two of the climate zones in GURPS, to help explain why so many different races coexisted:
Elves inhabited woodlands and jungles
Ghouls were native to deserts but had spread out widely as scavengers
Men inhabited plains
Nixies lived in rivers and swamplands
Selkies inhabited island/beach environments
Trolls inhabited arctic and mountain environments
Dwarves lived underground, in natural caves or in mines
From this, I defined body sizes. Trolls were comparatively large, SM +1, giving them an advantage in heat retention. Elves, men, and selkies were SM 0. Ghouls and nixies were SM -1, the former as an adaptation for recurring food scarcity, the latter to fit more conveniently into burrows or lodges. Finally, dwarves were the smallest race, at SM -2, letting them tunnel with comparatively less effort.
Going from this, I got base ST scores of 15 for trolls, 10 for elves, men, and selkies, 7 for ghouls and nixies, and 5 for dwarves. That gave me base weights of 445 lbs., 125 lbs., 43 lbs., and 16 lbs.
A specific tweak at this point was that I decided that dwarves, as miners, needed to be unusually strong, and in particular to have strong arms, like moles having massive forelimbs. I gave them, as a race, Arm ST +1, and boosted their body weight by 20%, to 19 lbs.
Next I looked at sexual dimorphism. I based this on the idea that male/female mass differences predicted mating patterns:
Males much larger than females went with polygyny and with strong male competition for dominance. I applied this to men and selkies, but with a difference of application: Men stayed comparatively close to home, forming long-term marriages or, if successful, harems; male selkies went out to sea for fishing, whaling, piracy, or trading, and brought back gifts to use in courting one or many female selkies. In both cases, I gave +1 ST to males (ST 11, weight 167 lbs.) and -1 ST to females (ST 9, weight 91 lbs.).
Males modestly larger than females went with a humanlike pattern of nonstrict monogamy, with successful males looking for a little extra. I applied this to nixies, whom I envisioned as in many ways the “human beings” of the world (the first farmers and city building), kind of the way hobbits are the “human beings” of Middle-Earth, with men as exaggeratedly heroic nomads and warriors. I didn’t treat this as leading to an ST difference between the sexes. Base nixie weight is about 1/3 base man/selkie weight, and if I divided the corresponding male and female weights by three I would get 56 lbs. and 30 lbs.; for lesser dimorphism I split the difference, with male nixies at 50 lbs. and female at 37 lbs.
Equal size and weight I envisioned as going with strict monogamy. I applied this to elves, whom I thought of as kind of like gibbons (musical, good at climbing, high DX).
I made female ghouls modestly larger than male, and gave them a hyenalike pattern where females were dominant and comparatively ferocious (and had enlarged clitorides used for threat display). I swapped the weight ratios for nixies, making female ghouls 50 lbs. and male ghouls 37 lbs.
Finally, for trolls, I had females much larger than males, with a social pattern where trollwives raised children on their own and needed to be large and ferocious to do so; male trolls wandered around in small groups (like the three trolls in The Hobbit) and from time to time showing up with presents. A 10% ST differential would have given trolls ST 13-14 and trollwives ST 16-17; I went with the narrower margin, making trollwives ST 16 and 512 lbs., and trolls ST 14 and 343 lbs.
Dwarves were again the weird race! I had decided to pattern their sociality after that of naked mole rats or the fortress eusociality of certain shrimp species. So a dwarf social group was one fertile female, a small number of fertile males who defended her mine and traded with outsiders, and a larger number of sterile offspring who mined and did supportive tasks. Both fertile sexes were the same size, but sterile offspring were SM -3 and ST 3 and weighed around 7 lbs.
I also looked at races being gracile or robust. I dealt with this not by making them heavier or lighter, but by making them taller or shorter for the same weight. Here men and ghouls were typical; elves were gracile; nixies and selkies (the aquatic races) were modestly robust, and dwarves and trolls were strongly robust. However, I also gave selkies plentiful body fat as insulation, making them Overweight: males 220 lbs., females 120 lbs.
Finally, I played with brain size. Brain size in mammals tends to be proportionate to body surface area; but human beings are about 8x the typical mammalian brain size, other apes about 4x, and monkeys (and songbirds) about 2x. Since GURPS says that humans have IQ 10 and monkeys have IQ 5, I figured that IQ varied as the square root of relative brain size. (That would give nonhuman apes IQ 7, which is reasonably close to the GURPS figure of IQ 6.) I gave elves +1 to IQ (about 20% more relative brain size) and ghouls and trolls -1 (about 20% less). But then I added another tweak: I decided that as trolls retreated into harsh environments, trollwives decreased in relative physical size, but not in relative brain size. So they ended up with ST +4 and IQ +1: As strong as trolls, but no stronger, but much smarter, fitting legends in which trollwives are powerful sorceresses.