Usage (case sensitive! Capitalize Half-Elf and Half-Orc!):
{{Race|Duergar}}
{{Race|Half-Elf|Half-Elves}}
Result:
Duergar
Half-Elves
If you want a bigger or smaller image specify so:
{{Race|Half-Orc|size=35}}
Result: 
Half-Orc
Usage (case sensitive! Capitalize Half-Elf and Half-Orc!):
{{Race|Duergar}}
{{Race|Half-Elf|Half-Elves}}
Result: Duergar Half-Elves
If you want a bigger or smaller image specify so:
{{Race|Half-Orc|size=35}}
Result: Half-Orc