Undercity sewers

The Undercity sewers, located close to the Undercity on the planet Taris, served as the meeting point of several sewage drains from the nearby area and were connected to other, similar sewage stations through a series of long metal pipes. Most of the complex was made of a permacrete-like material, bolted fast with metal bolts, as well as large, rusted metal sheets. The system, driven by perpetually moving gear trains, transported the waste into one of four large reservoirs while material removal was performed by droids, although these were largely absent or malfunctioning by 3956 BBY.

The Undercity sewer complex had at least one maintenance level, which was largely unsupervised by 3956 BBY, leaving the system of pipes in gross disrepair with raw sewage flowing directly through the level at several points. The stagnant stench of waste spread through the area, its odor reminiscent of the planet Gamorr. The walls of the maintenance level were decorated with simple, golden lines and circles in several places and were illuminated by a host of dim lamps.

The sewer system was established on Taris sometime prior to the Tarisian Civil War that took place a century before the Jedi Civil War to manage the sewage from the buildings surrounding the Undercity.

Somehow the Rakghoul disease ended up in the Tarisian Undercity. This caused the city to be abandoned, and the sewer system was left to deteriorate and was eventually overrun by Rakghouls and Gamorrean slavers but still served as the planet's understructure.

After the civil war that resulted in millions of civilian casualties, thousands of the poorer citizens of the Taris that rebelled were imprisoned. When the prisons couldn't hold the masses, the rebel prisoners were banished to the Undercity, where they formed a group known as the Outcasts. Rukil and his father and grandfather were among them, and when the inhabitants of the Undercity came to believe in a "Promised Land," a mythical location on Taris said to be completely self-sufficient, older generations of Rukil's family took a lifetime quest of searching for a path there. The two found their way to the depths of the sewers, where they eventually met their end, thus keeping the secret. In turn, Rukil spent his life seeking this mystical place with no success.

In time of the Jedi Civil War, maintenance of the system had ceased completely, leaving it rusted and malfunctioning. With the lack of upkeep, criminal elements disabled the manual locks of the maintenance levels of the facility, and it soon served as a hideout for Gamorrean slavers, who used many small sections of the vacant complex as holding cells for captives. The Black Vulkars gang, based in the Lower City, directly above the sewers, was forced to put up a defense system consisting of a ray shield and mine grids to keep elements from the Undercity wandering through the sewers to their headquarters. At some point, a rancor found its way into one of the maintenance levels of the sewers, settling in the northeast and surviving by eating the wanderers of the sewer.

In 3956 BBY, the Sith Lord Darth Malak's Sith Empire took over the planet and patrols were sent into the sewers to search for surviving crew members of the destroyed Galactic Republic Hammerhead-class cruiser Endar Spire. In particular interest to the Sith was the Jedi Knight Bastila Shan, a Human female capable of performing battle meditation. Several soldiers were killed by the sewer residents. At that time, Rukil, after following his father's and grandfather's footsteps, had found himself too old to continue the quest of searching the "Promised Land," and had sent in turn his young apprentice Malya to continue his work.

Shortly thereafter, former Dark Lord of the Sith Revan entered the Undercity in order to rescue Shan from the Black Vulkars. He employed local resident Mission Vao, a teenage Twi'lek, as his guide through the sewers to the Black Vulkar headquarters. In return, Revan agreed to save her Wookiee companion, Zaalbar, from the Gamorrean slavers in the sewers. Before Revan entered the sewers, he found the corpse of Malya, whose journal had information leading towards the sewage complex.

Upon descending into the sewers, Revan and his companions killed several victims of the rakghoul plague, beings mutated into creatures known as rakghouls that overran the sewers, and Gamorreans before eventually rescuing the Wookiee. In return for his assistance, Vao deactivated the shield hindering Revan's access to the Black Vulkars' lair from the sewers. While Revan and his friends fought their way through the sewers, they found remnants of Rukil's father and grandfather, and collected their journals that held their findings, which they would later return to Rukil. Through the passage, Revan then encountered the rancor in the northeast of the complex, but was able to overcome it to enter the base. After Bastila was eventually freed from the Vulkars, Malak ordered the Sith fleet to bombard the planet's surface to eliminate her, destroying the surface of the planet in which the rubble from the upper levels landed on the Undercity ground. This flattened large parts of the sewer system beneath, and most if not all of the remaining Gamorreans perished. This had ended the disorganized slavery in Taris's Undercity.

The Outcasts managed to descend from the Undercity into the sewers and make their way through what was left of the understructure during their months-long journey to the Promised Land. As they had survived the bombardment, they didn't encounter any other survivors of the bombardment in the sewers, Gamorreans or otherwise. Eventually, the Outcasts descended even further into Taris and made it to the Promised Land.

During the Cold War the Galactic Republic had settled on the ruins of Taris in hopes of rebuilding its city to prove that the Sith Empire could be defeated. Much of the sewer system remained, and different sections were converted into various facilities. But the Undercity was still overrun by Rakghouls, which had evolved to be more intelligent and use weapons, and a majority of them still lived in the sewers and would attack and infect travelers. Some of them had even evolved into Nekghouls but unlike the Rakghouls, the Nekghous couldn't spread infection. Governor Saresh struggled to stamp out corruption in the military and civilian forces across Taris. Thanks to her efforts and her dedication to the cause, the initiative was making more progress than it had in the last decade.

However, thanks to the assistance of various members of the Empire, Gravus succeeded in halting the project, and Taris, including the broken up sewers, were for an unknown period of time, consequently occupied by Imperial Forces.

By 3 ABY, much of Taris had been rebuilt, including the four cities above the planet's under structure, but it is unknown if the sewer system below had ever recovered.

The sewers were home to a number of criminal gangs and violent creatures. Notably, the Black Vulkars gang, led by Brejik, controlled both entrances to the upper sewers area. Additionally, a group of Gamorrean slavers operated out of the lower sewers, capturing passers-by and selling them to other criminal groups on the planet. People wandering the lower levels of Taris were unlikely to be missed, which substantially lowered the risk of the underworld denizens being discovered by Tarisian security forces.

Some inhabitants of the Undercity believed in the "Promised Land," a mythical location on Taris said to be completely self-sufficient. This belief, along with the desire to escape the poverty of the lower levels, caused at least three villagers to venture out in search of the fabled colony: Rukil's grandfather, father, and apprentice—Malya. All three found clues regarding the whereabouts of the Promised Land that pointed them towards the Undercity sewers, but they all perished within the complex.

Following the crash of the Endar Spire, several Sith soldiers were dispatched to the sewers and soon crowded the area. Several patrols were sent into the sewer complex to ensure that neither Bastila Shan nor any Republic soldiers escaped. At least a few of the participating Sith soldiers were violently killed.

Victims of the rakghoul plague were shut out from the Undercity by a large metal wall, forcing them to look for food and shelter in the sewer complex nearby. They soon inhabited large parts of the structure, becoming a threat to its other inhabitants. Another hazard to the public was a large rancor that managed to find its way into the sewers around 3956 BBY. It operated out of a large hall just outside the sewer entrance to the Black Vulkars gang's base, severely restricting access both to and from the hideout.

Although it was separated from the rest of the sewers by the aforementioned energy shield, the upper sewers contained several rakghouls and slavers. The area was effectively sealed off, the only two entrances being the corridor from the lower sewers and the elevator up to the Black Vulkars' base. The upper sewers originally had an additional entry and exit with a single ladder leading upwards, but it was blocked off by 3956 BBY.

The maintenance level, referred to as the lower sewers, was extensively overrun by criminals and animals, even more so than the upper sewers. Two ladders granted easy access to the level from the area directly surrounding the Undercity. Most functional doors in the area had manual locks that could be picked and bypassed. The level contained large groups of rakghouls while serving as the main base of the Gamorrean slavers. The Black Vulkars, fearing for their safety, set up a ray shield while heavily mining the level to sectionalize the sewers and protect their territory.

The Undercity sewers only appear in the video game Star Wars: Knights of the Old Republic. The player is required to visit the area in order to advance in the main storyline of the game. The area was designed, in part, by BioWare level artist Mike Trottier.

In dark-side non-canon ending, the player can choose not to return to the Undercity and keep the "Promised Land" journals, or the journals can be sold to Igear in the Outcast village, who destroys them, thus preventing the finding of the "Promised Land."

Taris Undercity reappears in roleplaying video game Star Wars: The Old Republic, where city remains are one of the places visited, sewers being indirectly mentioned.

• Star Wars Knights of the Old Republic: Prima's Official Strategy Guide
• Star Wars: Knights of the Old Republic Handbook