The most ancient and powerful race in the galaxy (or so they believe), the Protoss possess a highly structured society based on the preservation of their way of thinking. Highly intelligent and gifted with great psionic powers, they nevertheless suffer from a certain inflexibility that makes them extremely difficult to work with. Originally the Protoss were divided into several warring tribes, but they were united by a single Protoss warrior/philosopher, Adun. He is apparently responsible for strengthening the psionic racial link that all Protoss share, and he developed the Khala, a strict religion, philosophy, and social structure. Under the Khala, the Protoss have mostly abandoned their tribal lines and divided into three castes: Khalai, artisans and inventors; Templar, warriors and explorers; and Judicator, administrators and leaders. Terran dealings with the Protoss have been limited, restricting our knowledge of their abilities and equipment, but we do know that they possess extremely advanced technology, including warp-gate manipulation and energy shield generation. It is only recently that we have made significant progress in learning more about them.