Bobby was a family friend of the Winchesters and knew Sam since he was a little boy; Sam used to refer to Bobby as "Uncle Bobby". Sam's father, John, sometimes left Sam and his brother Dean in Bobby's care.
A flashback in "A Very Supernatural Christmas" revealed that Bobby gave Sam an amulet to give to John as a present; however, Sam gave this gift to Dean instead.
Season 2EditSam and Bobby meet again in Bobby's scrapyard where the nearly destroyed Impala sits. Bobby tells Sam the car can't be fixed, but Sam won't hear of it. Even if one part works, its good enough. Then Sam asks Bobby for the things John asked for. Bobby reveals to Sam that these items are not for protection from demons, but to summon them.
In Born Under A Bad Sign, a possessed Sam comes to Bobby's doorstep. Bobby is happy to see Sam and lets him inside. Bobby offers Sam a beer, but when "Sam" drinks it, he reacts to the holy water. Bobby had somehow known "Sam" wasn't actually Sam and knocks Sam out. Dean arrives, and he and Bobby try to exercise the demon out of Sam. Bobby notices though the demon managed to lock himself in Sam's body through a seal on Sam's arm. Bobby takes Sam's arm and burns the seal. Now with Sam back to normal, Bobby advises him not to talk about a hunter he murdered while possessed.
Later on, Bobby joins Dean in the hunt for the missing Sam. He and Dean arrive just in time to watch Sam get stabbed in the back. Bobby chases after Sam's killer, but Jake outruns Bobby. A week after Sam's death, Bobby comes to Dean suggests they bury Sam, but Dean tells him to get out. Bobby is surprised to see Sam when he arrives on his doorstep. Sam thinks that Bobby was the one who patched him up. Bobby doesn't have the heart to tell Sam that Dean lied to him and goes along with it.
Season 3EditWhile Sam is researching how to break Dean's deal, Bobby calls Sam and asks if Sam still has his nose in books. Bobby tells Sam, there probably isn't an answer in any books. Bobby tells Sam about some demon omens they should check out. After taking care of the seven deadly sins, Sam asks Bobby if there is knife out there that could kill demons. Bobby answers he hasn't heard of one until now.
In Bad Day At Black Rock, Bobby gets angry when Sam touches the cursed rabbit's foot. Sam tells Bobby he won't lose it but Bobby responds by saying that everyone loses it. So Bobby goes looking for a cure for this curse. In Dream A Little Dream Of Me, Sam and Dean try to figure out what happened to Bobby. Sam is concerned for Bobby, and when they hit a dead end, Sam gets the idea of asking Bobby for help (in his head of course).
In No Rest For The Wicked, Bobby finds a way to find Lilith. When they do find her location, Sam wants to go after her with Ruby's knife. Bobby agrees with Sam on the matter of summoning Ruby. When Dean shoots it down, Bobby leaves to go find something else. When the boys try to leave, Bobby reveals he took a part out of the Impala, and tells them he's coming too.
|“||Look, I know you hate me for suggesting it - I hate me for suggesting it. I love that boy like a son. All I'm saying is... maybe he's here right now, instead of on the battlefield, because we love him too much||”|
in When the Levee Breaks
Few months after Dean's death, Bobby and Sam lose contact with each other. When Dean returns, Bobby and Dean find Sam. In Are You There, God? It's Me, Dean Winchester, they investigate hunter's deaths where spirits are killing them. When Bobby goes missing in his home, they go looking for him. It is Sam who finds Bobby, trapped in an old car. He tries to pry the door open, but gets knocked back. Bobby misses the job and gets rid of the spirits.
In Yellow Fever, Bobby comes to help Sam when Dean gets ghost sickness. Bobby tells Sam what kind of spirit they are dealing with and Sam comes up with a plan. Bobby tells Sam this is a dumb plan, but Sam tells Bobby its the only one we got. Sam puts his trust in Bobby to make sure this plan works. When it does, Sam and Bobby tease Dean about it.
Then at the end of The Rapture, Bobby and Dean trick Sam into the panic room. While waiting for Sam to detox, Bobby suggest to let Sam out, so they can use him in the coming demon war. Bobby also believes that they, not the demon blood, are killing Sam. What they are trying to do, isn't working.
Then Sam escapes from the panic room and is attempting to steal one of Bobby's cars when Bobby comes with a gun. Bobby tells Sam he isn't going anywhere, but back into the panic room. Sam tells Bobby no, and says Bobby won't shoot him. Bobby resorts by saying don't test me. Sam walks up and grabs the gun's tip and points it at his chest. "Shoot," Sam tells Bobby. Bobby tells Sam they are trying to help him, but when Bobby doesn't take the shot, Sam takes the gun and knocks Bobby out.
Season 5EditBobby comes to bring the Impala back and helps them research the archangel Michael. Sam, not wanting to hold anything from Bobby, tells Bobby that he started the Apocalypse. "Bobby" gets angry and tells Sam after all this, to lose his number. Sam is very hurt by this and agrees to do this. Sam leaves to go do some research. When Bobby is put in the hospital, Sam doesn't want to leave, but Dean convinces him to go.
After a run in with the angels, Sam and Dean are in Bobby's hospital room. As the leave, Bobby tells Sam what he said eariler was not him, but the demon. That and no matter what Sam has done, Bobby will never stop contacting Sam. Sam visibly shows that he is thankful and relieved at Bobby's words.
In Dead Men Don't Wear Plaid, Sam and Dean get worried about Bobby when his wife come back from the dead. They ask Bobby what he would do if he was in their situation. Later Sam saves Bobby and Dean. In Point of No Return, Bobby helps Sam keep Dean on a leash when Dean decides to say yes to Michael.
When Dean leaves with Crowley, Sam calls Bobby in The Devil You Know. Sam first talks about how Dean just left him and Bobby talks to him about it. Sam also asks how Bobby overpowered the demon that possessed him. Bobby answered he just did. Then Sam suggests a plan to get Lucifer into the cage. He suggests that he says yes to Lucifer and jumps in the hole. Bobby angrily ask Sam "Are you trying to kill me?". Bobby continues on by saying what he did was a stroke of luck, and it wasn't Lucifer. Sam says its the only plan they got and they have to try.Bobby does go along with Sam's plan and they tell Dean. When they find out that Bobby sold his soul, Sam asks:
|“|| Sam: Did you kiss him?|
Sam: Just wondering.
— Sam and Dean
in Two Minutes to Midnight
Now with only one ring left and the threat of Croatoan, they split up. Sam and Bobby (plus Castiel) go to stop the spread of Croatoan. There Bobby watches in awe as Sam keeps recusing people and doesn't stop. This leads Bobby to the thought that Sam could actually get control over the devil. So Bobby helps Sam collect the demon blood necessary to allow Lucifer into Sam's body without burning up.
Before Sam goes to drink the blood and say Yes to Lucifer, Bobby says goodbye to Sam. He tells Sam he'll see him around. Sam repsonds see you around and gives Bobby a hug. Then Bobby tells Sam to fight Lucifer tooth and nail. Don't give an inch. What's touching is Sam responds to Bobby like how Sam used to respond to John, with a "Yes Sir".
Season 6EditUnlike Dean, Bobby knew Sam was back for a while now. He just didn't tell Dean. In You Can't Handle The Truth, Bobby tells Dean that Sam is the better hunter lately. Other than talking about Sam with Dean, Bobby and Sam don't have much contact with each other until later when Dean finds a way to get Sam's soul back. In Appointment In Samarra, Dean leaves Bobby to watch Sam while he goes to become death for the next 24 hours.
Under Bobby's watch, Sam manages to slip away and summon Balthazar (tells Sam he needs the blood of a "father" in order to reject his soul). When Sam returns, Bobby knows something is up and knocks Sam out when Sam attacks Bobby. However, when Bobby turns his back, Sam slips away. So Bobby quickly locks the door to the basement and locks himself in the closet. Sam finds him and starts to break the door down with an axe. Bobby tells Sam he beter not say heres Johnny. Sam tells Bobby hes, trapped, but Bobby begs to differ when he pulls the latch on the trap door. Bobby asks what Sam's plan is, but gets no response. Bobby yells to Sam, even though he does care for Sam, he will still blow his legs out. Bobby heads down to see Sam is no longer there and heads outside where Sam knocks Bobby out.
Sam ties Bobby to a chair and tells Bobby hes sorry but there is no other way. Just as Sam is about to kill Bobby, Dean knocks Sam out. When Sam does get his soul back (Like A Virgin) he gives Bobby a big hug and asks how Bobby is still alive. Sam reveals that he has no memory of whats happened the last year and a half, which surprises Bobby. Although the fact that Sam tried to kill Bobby is still fresh in Bobby's mind, and its hard for him to be around Sam. But because Sam is like a son to him, Bobby doesn't tell Sam what Sam tried to do.
Bobby does eventually forgive Sam, and they team up in Mommy Dearest. Sam and Bobby look together for the good doctor who had called for help. Then the police show up and they claim to be FBI agents. Bobby gets rid of the police by lying and gets rid of the APB. Sam is impressed by Bobby's trick to get rid of the police.
In ...And Then There Were None, Bobby meets Samuel Campbell (Sam and Dean's grandfather) and stands up for Sam and Dean against Samuel. Samuel retorts by saying Bobby is the man pretending to be Sam and Dean's father. Bobby turns this around by voicing disgust at Samuel for selling his own blood out to monsters.
Sam also agrees with Bobby's idea of Castiel working with Crowley. So while Dean distracts Castiel, Sam and Bobby interrogate a demon on Crowley's location.
Bobby also gets worried when Sam goes into a comatose state when Castiel breaks down Sam's wall in The Man Who Knew Too Much. They put him into the panic room with enochian sigils all over the room to protect Sam.
|“||You worry about him, all he does is worry about you. Who's left to live their own life here? The two of you. Aren't you full up just playing Snuffleupagus with the Devil all the livelong?||”|
— Bobby about Sam and Dean
in How To Win Friends and Influence Monsters
In Hello, Cruel World, Sam tells them about his hallucinations, and that hes seeing Lucifer. So Sam is forced to stay behind, with Bobby watching him. Bobby is fatherly towards the fact the Sam is seeing hell, and is constantly telling Dean to go easy on Sam.
In How to Win Friends and Influence Monsters, Bobby and Sam talk about how things are going. Bobby asks about Sam's mental state and Sam comments that he has it under control while touching his scar. Bobby doesn't believe this but lets it go. While rescuing Bobby from the Leviathans, Bobby is shot and Sam is the one who finds a bloody bullet hole in Bobby's hat. While racing to the hospital Sam is in the back checking and helping Bobby.They manage to get Bobby to a hospital. Sam is not optimistic about Bobby's situation, and attempts to hold his memories of hell back due to the emotional ride Sam is feeling from Bobby, who is fighting for his life. Sam and Dean come to say their final goodbyes when Bobby comes to and grabs Sam's hand. With one final act he writes numbers on Sam's hand and passes. Sam watches in horror as Bobby is tended to, but to no luck. Bobby passes and Sam mourns the loss. Few weeks after Bobby is gone, Sam is wondering if they should tell people that Bobby is gone.
Although Sam had a feeling that Bobby was still around after the beer disappears and tried to contact Bobby. But with no proof Sam believed Bobby to be deceased. In Of Grave Importance, Bobby reveals his existence and Sam is shocked to see that Bobby is still around. Sam quickly realizes that it's the flask. Later on, Bobby becomes visible to Sam, and Sam realizes why he couldn't make contact with Bobby since he was always with Dean who had the flask. Sam is optimistic about Bobby's situation, but like Dean, he is worried about Bobby.Sam's optimism about Bobby slowly fades as he begins to worry that Bobby is slowly becoming an angry spirit. In Survival of the Fittest, Sam quickly notices that Bobby had possessed the maid from the motel, and moves to stop Bobby. Sam approaches Bobby and asks him to stop. Bobby responds by grabbing Sam by the neck and choking him. Bobby soon realizes what he's doing and leaves the maid's body. Bobby later returns to say his final goodbyes before his flask is burned.
Season 8EditIn Taxi Driver, Sam learns that Crowley had bargained to bring Bobby's soul to Hell instead of going to Heaven. So after Kevin tells them that they need to save an innocent soul from Hell, Sam is determined to save Bobby. Sam goes down to Hell and finds Bobby's cell. Sam is happy to see Bobby and Bobby punches Sam thinking he is one of the demons tormenting him. Sam proves to Bobby that it's him and they hug. Sam leads Bobby out of Hell when they run into another demon looking like Sam and Bobby takes a chance and stabs one of the Sam's which luckily turns out to be the demon one. Sam leads Bobby into Purgatory where Bobby berates Sam for leaving Dean there for a year, telling him that he taught them the "leave each other behind" rule and that its crap. Bobby initially wants to remain on Earth as a ghost again, but Sam is able to convince him to help them complete the trials by ascending to Heaven. Bobby escapes to Earth in Sam's arm and Sam releases him to Heaven where he belongs. Crowley briefly stops this, but Naomi intervenes and thanks to Sam's efforts, Bobby is now finally in Heaven.
Season 9EditInI Think I'm Gonna Like It Here, "Bobby" returns in Sam's mind while Sam is in a coma. He represented the side of Sam who wanted to die. In this dream Sam was surprised and glad to see Bobby again. Bobby quickly takes Sam away from "Dean" (the side of Sam who wanted to live), and Sam looks to Bobby for advice on what to do. Bobby tells Sam it's his choice and points out that Sam has done a lot for the world, including saving it. Bobby points out that Sam is leaving behind a legacy. Bobby takes Sam to a cabin, telling Sam everything he needs is in that place. Bobby tells Sam he'll be waiting for Sam in Heaven with a "couple of cold ones". Then "Dean" returns and stabs Bobby and Sam is shocked by this. This sparks Sam to get rid of "Dean".
Season 10 Edit
Sam and Castiel conspire to get the angel Metatron out of Heaven so they can inquire him on the cure to the Mark of Cain, which Dean possesses and is doing damage to Dean. They decide to contact Bobby. Using a psychic, Castiel is able to communicate with Bobby and have him open the doorway to Earth.
Sam stays behind as Castiel enters Heaven to retrieve the former Scribe. Following the mission's success, Castiel passes on a letter to Sam from Bobby. The letter is full of words of encouragement, causing Sam to nearly cry.
Season 11 Edit
Sam and Dean work on two cases involving Soul Eaters that Bobby once dealt with.
After discovering that the British Men of Letters possess the Colt, Sam reveals that Bobby taught him the ritual to create new bullets for the gun. When Sam mentions a friend had taught him, Mary Winchester immediately realizes Sam means Bobby which he confirms.
- Bobby's actor said that he believed Bobby kept a close eye on Sam out of worry about Sam's dark side.
- They both lost a woman they were in love with due to demons: Sam lost Jessica and Bobby lost Karen.
- Bobby admitted in You Can't Handle The Truth that, while he favored Dean over Sam, Sam was (at the time) the "better hunter."
- Bobby and Sam have both been possessed by demons: Bobby by one of Meg's minions and Sam by Meg herself and Crowley.