"Goblins! Why did it have to be goblins?" -Morgnan
Homeland: Zagraz Mountains
Goblins exist on a tribal level. A tribe is a social group that exists outside of or before the development of states. The governmental systems are rudimentary and the rules are usually simple. Goblins typically are led by chiefs, whose tribes occupy a certain territory, but they do not have borders and control land in the same way a state would. Tribes arise out of common bonds of related or united families, which in turn coalesce to form an identity with a common history. This has the potential to make a tribe a very tight-knit social structure, if a very exclusionary one.
The main disadvantage to a tribal existence is the lack of sophisticated social mechanisms needed to developed advanced technology. The only driver of innovation in goblin tribes is that of survival, rather than creativity, scientific curiosity, or profit motive. Hence, a tribe's customs, weapons, tools, religion, and magic are heavily tied to the environment around them. This, combined with the goblins' small size, makes them a very backward enemy to deal with, and they are rightfully considered targets for less experienced adventurers.
Goblins generally use their entire adult and adolescent male population to fight. This contrasts greatly with many civilized realms, which often restrict access to weapons to a small class of fighters, such as a standing army, mercenary groups, or feudal retainers loyal to specific lords. In a sense, the goblins use a militia to fight with, as there is generally little distinction between a farmer and a warrior, or someone who works and someone who fights. Female Goblins fight when they have to, but are generally left at home to raise more young; this is not necessarily done out of sexism, but necessity, as Goblins always have to replenish their numbers given their high mortality rates and lack of individual strength relative to most other sentient species.