From the publisher blurb:
Deep beneath the world of man all the ancient races still abide. The most numerous are the Goblins who make their living by stealing from the world of man and doing the bidding of more powerful beings.
Life for a Goblin is nasty, brutal and short, so they form gangs for mutual protection. These are rules for playing these Goblins in the modern world. Goblins form gangs for mutual protection and amusement while adventuring. Goblins run by players should all be part of the same gang.