Three Dog is the radio host, DJ, and news anchor of the Galaxy News Radio station in the Capital Wasteland in 2277, playing music that would have been heard on the radio in the years leading up to WWII, as well as the immediate post-war era.
Born to parents who made their way in the world as members of a traveling theater group, Three Dog grew up listening to rock music, resenting the government that he never knew (but surely caused the Great War), and fully believing in the rights of free speech and communal law. He is fully committed to "spreading the signal" of his radio station to anyone who will listen; it is his duty to counter the propaganda spouted by the Enclave on their station.
At some point before he established GNR, he was taking Jet and stumbled across Oasis. He established GNR in 2272, together with Margaret. Since he began, he has been broadcasting to the Wasteland with public service announcements and music. At times he makes jests at Enclave Radio, going as far as mocking President John Henry Eden's voice.
Three-Dog believes in what he calls "fighting the Good Fight," which boils down to noble pursuits in the fight against raiders, super mutants, slavers, Talon Company, and the Enclave. This explains why he cooperates with the Brotherhood of Steel. However, he does not do any physical fighting, nor does he help to coordinate or organize it.
Galaxy News Radio: Failing, or not taking the aforementioned speech check starts this side quest. If the Lone Wanderer passes that Speech check, they can immediately reinstate conversation to have both quests running at the same time. The Wanderer can also come back later, or see him for the very first time after having made progress otherwise in the main quest to find father James, and if player character can bring support to Three Dog's "good fight," Three Dog will also give the Lone Wanderer this quest.
Killing Three Dog before he tells the player character to go to Rivet City at the end of the quest "Galaxy News Radio" starts the quest The Search Continues.
Evidently, his broadcasts are pre-recorded. He can be viewed at the GNR HQ, not doing anything of note, but still his public service announcements or other news can still be heard on the radio. This is further supported by the fact that he can be heard on the radio at any time during the day. Additionally, he often says in his introduction "coming to you taped from my fortified bunker in the middle of a DC hellhole" though he also will say "coming to you live."
If Three Dog dies, Margaret will become GNR's broadcaster. However, she will be extremely unmotivated to do this job, and mention that Three Dog was murdered, over and over again. The achievements of the Lone Wanderer will not be mentioned by her.
If the player character helps Roy Phillips get into Tenpenny Tower, Three Dog later refers to the "wholesome slaughter" of the former residents, instead of the common expression "wholesale slaughter."
Three Dog's broadcast expression can change depending on the actions of the Lone Wanderer. Should the Lone Wanderer pursue a noble, good-Karma path, Three Dog will say "Nice goin' kid!" at the end of an event-determined broadcast. But should the PC choose an evil, bad-Karma path, Three Dog is quoted as saying "Not cool kid. Not cool at all" or "what's with that, kid?"
If the player character has completed a task that Three Dog comments on during a broadcast, but the player character's overall Karma is opposite of what completion of that task would provide, Three Dog's report will seem to refute itself. Example: If the player has Evil Karma but has completed Those! by helping Bryan Wilks, Three Dog will open his monologue condemning the Lone Wanderer, then switch to praising them for their efforts in Grayditch.
Oddly, having the title "Urban Avenger" makes Three Dog refer to the Lone Wanderer as an "urban defender". Whether this is a typo, or simply an overlooked recording mistake is unknown.
Three Dog plays the same songs over and over again because they are the only ones he could find in working condition.
The name of the character Three Dog is shared by a character played by his voice actor (Erik Dellums) "Dog 3" in the film She's Gotta Have It.
Erik Dellums helped develop the character, including his signature howls.
In Borderlands 2, there is a shotgun called the "Dog" which commonly spawns with the prefix "Thre." Its description is "One barrel isn't enough and two is too few," similar to one of Three Dog's sayings in Fallout 3.
pcps3xbox360 Occasionally, Three Dog will mention events that occur after the ending of the game. He will only do so if the player had downloaded the Broken Steel downloadable content and has not played through the part in the game before it. [verified]
pcps3xbox360 Sometimes after starting a new game, Three Dog can be heard stating things that haven't come to pass yet. This has been known to last until you catch up with the event that he's referring to. [verified]
ps3xbox360 Sometimes Three Dog will start saying a comment and then quickly switch comments about the player over and over again. This can prevent you from listening to music for the rest of the game. [verified]
pcps3xbox360 Occasionally Three Dog will repeat the "News" section of the broadcast 2-3 times over until he later continues playing songs again. [verified]