Goblins are a common and often fairly weak humanoid monster found in the popular Dungeons & Dragons universe - unlike many other realities Goblins are not considered smaller "cousins" of the orcs in this setting and stand as a species in their own right: though they are considered somewhat related to beings such as Hobgoblins and Bugbears, which make up the goblinoid family. Goblins are based on the mischievious and often ugly monster from folklore, who were believed to cause trouble for people in a manner similar to modern accounts of poltergeists or "unclean spirits".
D&D Goblins, like other goblinoids, have a commonly short temper. Leaders among the race often come to power through betrayal or aggression, rather than by more peaceful means, or as clerics of the goblin gods As such members of the race are more easily provoked than individuals of most races and often take sadistic pleasure in exacting revenge once crossed. Goblins who turn away from evil often find it difficult to overcome this short fuse and have a sense of greed that makes it difficult for them to act altruistic. Those that do often make use of their ill-gained talents as rogues or fighters.
Being bullied by their bigger, stronger cousins Hobgoblins and Bugbears, has taught goblins to exploit what few advantages they have: sheer numbers and malicious ingenuity. The concept of a fair fight is meaningless in their society. They favor ambushes, overwhelming odds, dirty tricks, and any other edge they can devise. Goblins prefer to fight battles where the odds are in their favor and often flee or surrender when outmatched.