Dad

 is the Lone Wanderer's father and Vault 101's resident doctor in 2277.

Background
James was born in 2226.

He was the chief scientist and project leader of Project Purity, an ambitious private project intended to cleanse all of the radioactivity from the water of the Potomac River that fed into the entire Capital Wasteland. However, when his wife, Catherine, died giving birth to the Lone Wanderer, he gave up on the project over the grief of losing her. He then asked for entry for himself and his child into Vault 101 in return for becoming the Vault's new physician, and the Vault Overseer granted his request.

Quests

 * Baby Steps: James puts the baby Lone Wanderer in a playpen in a room which contains the You're S.P.E.C.I.A.L.! book. After a brief absence, James returns and shows the child Catherine's favorite Bible quotation.
 * Future Imperfect: James has a brief conversation with his now-teenaged child before it is time to take the G.O.A.T..
 * Escape!: James' unexpected absence from Vault 101 prompts a security crisis and propels the Lone Wanderer out into the wastes.
 * Following in His Footsteps: The Lone Wanderer searches for his/her dad. He/she can either go straight to Vault 112 (where he is being held); or he/she can go to Megaton, which directs him/her to Galaxy News Radio, which directs him/her to Rivet City, which directs him/her to the Jefferson Memorial which then leads him to Vault 112.
 * Tranquility Lane: James finds himself in Vault 112, held prisoner in the form of a dog in a virtual neighborhood created and controlled by Dr. Braun.
 * The Waters of Life: Father and child make their way first to Rivet City, then to the Jefferson Memorial, the site of Project Purity. As the Enclave storms the Memorial, James refuses to cooperate with Colonel Augustus Autumn. In the end, James floods the room with radiation, attempting to kill Autumn but killing himself in the process (Autumn, however, survives). The last time the Lone Wanderer sees him is when James presses himself against the blast door of the activation room, and telling his child to "Run!" as he slumps to the floor, thus sacrificing himself so his child could live.

Other interactions

 * Birth Scene: James delights over the birth of his child, presenting the child to his wife, who expresses pride and happiness before going into cardiac arrest. James attempts, unsuccessfully, to save her life.

Effects of player actions

 * When the player is doing tasks to make Project Purity work, James will say that he heard of the player's actions. His reaction will change depending on how you resolved the quest Power of the Atom. If you disarmed the bomb, he will ask you if you truly did it, and will be proud of you if you say that you did. If you caused Megaton's destruction and admit it to James he will be disappointed (you can lie to him, but he won't really believe you unless you have very high karma).
 * If you did not resolve the Power of the Atom quest at all, or if you talk to him again after he comments on the aforementioned quest, he will instead comment on your current karma level. If you have good karma, he will say "You're a good person, and it shows". If you have bad karma, he will instead comment on how you "seem troubled, like there is a cloud hanging over you." If the player has neutral karma he just greets you in the default manner.

Inventory

 * † Only while in Vault 101.
 * ‡ On his way back to Rivet City.

Notable quotes

 * "As far as I can tell, you're a perfectly healthy 16 year old boy/girl."
 * "Son/Honey, I brought you into this world, I think you know the rest."
 * "Agghh! What in God's name is wrong with you?"
 * "Stop screwing around!"

Appearances

 * appears only in Fallout 3. A photograph of him appears in Fallout: New Vegas.

Behind the scenes

 * James' voice is provided by actor Liam Neeson, after whom the character is also physically modeled. "This role was written with Liam in mind, and provides the dramatic tone for the entire game. "Liam is absolutely amazing to work with," said Todd Howard, Executive Producer of Fallout 3. "It’s been a pleasure bringing the father to life and working with the wonderfully talented people at Bethesda on Fallout 3," said Neeson. "I hope the fans of the franchise and the game will be excited by the results."