Vault 15 Vault 15 is a location in New California in 2241 . Background . Like many of the vaults , it was part of Vault - Tec ' s grand social experiment . The Fallout Bible ( by Fallout 2 / Van Buren ) says the experiment in this vault entailed that it was to stay closed for fifty years , populated by vault dwellers of extremely diverse ideologies and cultures . The situation caused by the experiment led to a great schism , during which four groups ultimately left the vault to brave the wastes during the spring of 2141 . Three of these groups became roving gangs of raiders : the Jackals , the Vipers , and the Khans in the winter of the same year . The fourth group settled down a few miles west of the vault and founded the village of Shady Sands in the spring of 2142 . While the three gangs harassed the village and each other over the years , Vault 15 itself gradually fell into disrepair . By the time the Vault Dweller came across it in his search for a replacement water chip for Vault 13 , it was already ransacked and had also undergone complete power failure , several cave - ins , water damage , and other catastrophes . The intervening years has not done anything to improve the vault , but they have brought new occupants . When the Vault Dweller massacred the Khans in 2161 , a sole survivor named Darion was overcome with guilt because he alone had survived when the rest of the gang died . Darion then spent the next 8 decades of his life rebuilding his petty tribe to the once great gang that scoured the wastes , also out of revenge against Tandi and the Vault Dweller . The result was the New Khans . A small settlement of squatters has made its home at the entrance to Vault 15 . The squatters forge a precarious existence there by the sufferance of the gang . Shortly after , the squatters allowed Darion and the rest of the New Khans to move into the vault itself on the condition that they repair the vault ' s systems in order to help provide the squatters with food , water , and other amenities . At first , this setup was advantageous enough that the squatters rejected all efforts by the NCR to annex them or even gain simple access to the vault . Then , the Chosen One came along . President Tandi hired them to infiltrate Vault 15 - or at least get the squatters to allow NCR access - to retrieve computer parts and other equipment vital to the NCR ' s continued expansion . While accomplishing this quest , he discovered the truth behind Darion ' s operation ; he and his men were actually a band of raiders calling themselves the New Khans , using the vault as a base of operations towards Darion ' s goal of revenge against Tandi and everything the Vault Dweller stood for . Also , the food and water that he had been providing the squatters with didn ' t come from the vault ' s systems after all , but the spoils from raids the New Khans had been running along the wastes between NCR and Vault City . After Darion was killed by the descendant of the man he had sworn vengeance against nearly eighty years earlier , that very same man brokered a deal with the squatters , who accepted the NCR ' s assistance . With the support the Chosen One secured from the New California Republic , the Vault 15 squatters soon became self - sufficient and productive members of society . The Chosen One ' s help with Vault 15 launched the New California Republic ' s push to civilize its neighbors . Though there were many more obstacles to overcome , the NCR now had a foothold into the northern wastes . Layout . Surface ( " Fallout " ) . A small building sitting in the middle of an empty space . This entrance will be guarded by a radscorpion if you are unlucky . The squat ( " Fallout 2 " ) . A grouping of tents , small buildings and some trees up against the side of a cliff . There are squatters wandering the area . Eastern entrance ( " Fallout 2 " ) . Raiders built a lift to have an easy access to the vault , bypassing the squatter residents and built a shack for its protection . This shack is the place where Chrissy is kept . Entrance ( " Fallout " ) . This area has the same layout as Vault 13 ' s entrance . On the first corridor you will find a mole rat . At the end of this area you will need a rope to go further down into the vault . Entrance ( " Fallout 2 " ) . This area has almost the same layout as Vault 12 ' s entrance , except that the outside section is a cavern instead of a sewer , and the main entrance elevator with a tunnel leading to it is present . This is completely different from what the Vault Dweller saw there in 2162 . After you repair the power generator on level 2 , you need to deal with a force field to proceed . Living quarters ( " Fallout " ) . This area has a layout much like Vault 13 . Here most people will get their first armor . You will again need a rope to go down further at the end of this area . In the 3rd room counting from the left , you can find a locker with a rope in it . Living quarters ( " Fallout 2 " ) . This area has no rubble . There is also ( with a good repair skill and a tool ) a generator that can be repaired , this turns on the lights and the console to activate the level 1 force field . Also worth noting is the fact that all three levels are connected by a single elevator , which is different than the two shafts seen in Fallout . The presence of a wall locker in one of the rooms bears a resemblance to Vault 12 . Command Center ( " Fallout " ) . Much of this level is buried under tons of rock and rubble , including the command and control center . The rest of the vault ' s equipment has been ruined or destroyed . There are a lot of pig rat s , rats , and one mole rat . Command Center ( " Fallout 2 " ) . The command center is in control of Darion , the leader of the New Khans . Though most of the computers have been destroyed , there are a few of them that work . . . barely . Appearances . Vault 15 appears in " Fallout " and " Fallout 2 " and is mentioned in the " Fallout Bible " . Bugs . Certain raiders in the vault are bugged . Some have incorrect ammo or ammo in their item slots which confuses the AI and prevents them from using their weapons correctly . Notably , Darion will not use his flamer and will run away from the player once combat has started .