Vault 13 Overseer

Overseer Jacoren is the leader of Vault 13 around 2161. His name is never given in the game, but could be seen on the concept art. He was fully aware of the Vault Experiment program conducted by the Enclave, and therefore tried to do everything to keep the Vault closed for 200 years, just as the Program wanted it to be. As it is quite unlikely that he could have been more than 100 years old, the knowledge about the experiment was probably passed to him from the previous Overseer, most likely one of his parents.

Background
When the Vault's only functioning water chip got damaged and shut down, he sent one of the vault dwellers, who later became known as the Vault Dweller, into the wasteland to find a replacement chip. In the course of his adventure, the Vault Dweller ended up defeating the mutant threat, and was subsequently expelled from Vault 13, as the Overseer thought that he would ruin the Vault Experiment by convincing people to leave the Vault.

Despite Vault Dweller's exile, many people chose to follow him into the Wasteland. The Overseer tried to stop them and was eventually tried and sentenced to death for his crime, probably after the dwellers learned about his involvement in the Experiment.

Interactions with the player character
Overseer Jacoren can give you the 3 main quests: finding the water chip, killing the Master and destroying the vats in the Mariposa Military Base. Also, if your Character has the Bloody Mess Trait, the Title Berserker or low karma, right after the Overseer's goodbye speech at the end of the game, the Vault Dweller will automatically put away his weapon, draw a pistol and shoot the Overseer in the back. It is also possible to kill the Overseer by pressing A key just after his speech and putting him down with one critical shot. This ending is not considered canon, as it is recorded elsewhere that the Overseer survived and was later tried and sentenced to death. However, this recording might be a mistake, a misrepresentation of how he died, so there is still a possibility that the Overseer died by the hand of the Vault Dweller.

Tell Me About
You can ask the Overseer about the following words:
 * Chip
 * Healing
 * Library
 * Medic
 * Outside
 * Overseer
 * Vault
 * Vault 13
 * War
 * Water
 * Waterchip

Appearances in games
The Overseer appears in Fallout as a Talking Head voiced by Ken Mars.

Quotes

 * I always thought of Fallout's story of drawing straws was something the Overseer thought of. "Look, someone has to go outside, and they may die out there, so let's draw straws". Someone, probably not the Overseer since he wouldn't have gone outside no matter what, demanded that EVERYONE draw a straw in order to be truly fair. But to be honest, the vault dwellers were simply terrified of going outside, and terrified people do not always make the wisest decisions.

Anyway, when big dumb Larry drew the straw, maybe the Overseer saw a way to rid their limited gene pool of some really bad alleles. - Tim Cain at DAC forum