The Sith holocron was a device of the Sith dark side order that recorded Sith teachings. The holocron was red in color and the size of a Human fist. It was pyramid-shaped and was made from a crystalline or glasslike material. It had a fragile appearance and bore a slight crack on one face. The holocron contained three gatekeeper personalities that could impart knowledge onto the user, being Sansin Koriss, Dargous Tanmoul and Bavik Vannor, each of which could be activated by pressing one of the holocron's side panels. No advanced mastery was needed to access the device and the three personalities would willing interact with anyone who activated the holocron. The gatekeepers sought to coerce the device's users into accepting the dark side of the Force and warned of impending doom if the user failed to do so.
The gatekeeper Sansin Korriss was projected by the holocron as a silver-tongued Sith apprentice clad in long robes and jewellery, and displaying a constant smile. The Korriss personality would bargain with users of the holocron in his dealings with them; he possessed deep knowledge of the dark side but questioned whether the user was worthy of his guidance. As a powerful Sith battlemaster, the gatekeeper Dargous Tanmoul was clad in dark-colored Sith armor with a Sith sword slung at his side. He spoke in a blunt manner and provided insights on the use of the Force to achieve victory in battle, seeking to use his brutal descriptions to drive others to feelings of anger and rage. Tanmoul was the least likely of the three gatekeepers to attempt to subvert the user to the dark side, though the gatekeeper felt insulted if this was highlighted to him; he admired strength and savagery and would offer to train individuals who exhibited these traits. The gatekeeper Bavik Vannor was a fallen Jedi Knight and claimed to be uncertain as to why his likeness had been included in the holocron. The Vannor personality portrayed himself as remorseful about embracing the dark side, though in truth he considered the dark side a great ally, and he would regale users of the holocron with details of various horrors and atrocities in hope of causing the user to surrender to their emotions.
The holocron was constructed by the Sith Empire and taken by the Sith adept Valik Kodank when she fled Sith space at the end of the Great Hyperspace War, a destructive conflict between the Sith and the Galactic Republic fought in 5000 BBY. Kodank studied from the holocron and the device came to be housed within the Temple of Pain, a Sith temple constructed by Kodank on an asteroid within the depths of the Tascollan Nebula. The holocron was stored inside a small, four square meter room in the temple, floating one meter above the ground in a repulsor field.
Thousands of years later, during the time of the Galactic Civil War, Kodank's spirit trained the Dark Jedi Thaum Rystra as her apprentice and Rystra utilized the Sith holocron to further his knowledge.
In around 7 ABY, Rystra lured a group of New Republic agents to the Temple of Pain as part of a scheme by Kodank to possess the body of the Twi'lek Force adept Sha'lia. As the agents progressed through the temple, they came across the room housing the holocron and examined the relic. The artifact's gatekeepers interacted with the agents and all three tried to convince the team to embrace the dark side. Vannor versed the agents in Valik Kodank's personal history, while Koriss revealed that Kodank was fearful of an Sith amulet in her personal chambers that could focus the Force power of the user. The Sith apprentice further insisted that the agents take the holocron with them so that he could assist the team in challenging Kodank. The agents subsequently departed and fought Kodank's spirit shortly thereafter.
The Sith holocron appeared in Light and Dark, a 2002 roleplaying adventure by Lee Pickler published by RPGA as the final instalment of the Child of Light saga and which is set within Star Wars Legends continuity. In the adventure the players roleplay as the New Republic agents that venture to the Temple of Pain and it is possible for the player characters to interact with the holocron and its gatekeepers, and even to remove the relic from its repulsorfield and take it with them.