The Klingon Defense Force (KDF) is one of the main playable factions of Star Trek Online.
The KDF is the military arm of the Klingon Empire. Klingon culture values tradition, ritual, and above all, honor. All Klingons are expected to become warriors, and those who are unable to fight are obliged to commit ritual suicide. Since the events of Star Trek: Nemesis, the Klingon Empire has expanded its territory, notably its take over of the Gorn homeworld, but also various other species such as the Nausicaans and the Orion. As such these species serve in the KDF.