Jake Chambers, an eleven-year-old boy from the New York of 1977, is the symbolic (and later adopted) son of Roland. Jake's given name is John, but he prefers to be known by Jake, and is called "'Bama" by his house-keeper, who is far closer to him than his parents. In his home world, he dies at the hands of Jack Mort (who Jake initially believes is Walter) and ends up in Roland's world as a result. The gunslinger and the boy travel together in pursuit of the Man in Black, developing a strong bond along the way. However, in order to reach the Man in Black, Roland lets Jake fall to his death.

The child Roland allowed to die reappears in Roland's mind in The Waste Lands, however, due to a paradox. Since Roland (in The Drawing of the Three) prevented Mort from shoving Jake into traffic, he never died, therefore he never appeared in Mid-World and was never left to die under the mountains. Jake and Roland, however, can remember both timelines, and the knowledge is slowly driving them insane.

In the first half of The Waste Lands, Roland's ka-tet figure out a way to draw Jake into Mid-world, where he belongs (an action which finishes the real Drawing of the Three, Jack Mort never having been intended to join the ka-tet). Eddie is driven to whittle a key out of wood as they approach a Speaking Ring, where Eddie draws another door into the ground, this one guarded by an invisible demon. Susannah distracts the demon by allowing it to copulate with her, while Eddie perfects the key and uses it to open the door. On the other side, Jake has been led by the younger version of Eddie who lived in that when to a haunted house (indeed, Eddie has vague memories of the encounter himself), filled with evil spirits and a horrendous gate-keeper. Jake, with some timely assistance from Roland, fights through them to reach the door. Once the boy is in Mid-World again, Roland's and Jake's memories are merged and their descent into insanity abated. Unfortunately, Susannah will pay the price for her sacrifice in distracting the spirit.

While crossing the desolate city of Lud, Jake is kidnapped by a deranged resident of the city. He allows himself to be taken in exchange for the rest of the group's safe passage, and Roland promises to come for Jake, despite having to abandon him temporarily. Despite the danger it poses, he rescues Jake, reaffirming the father-son bond that has grown between them. Like Eddie and Susannah, Jake shows amazing aptitude to the way of a gunslinger.

Jake is the second member of the ka-tet to die, when he sacrifices himself to save Stephen King (as a character in the series) from certain death by putting himself between King and the van meant to take his life. By the end of the tale Jake has died a total of three times. An alternate version of Jake is encountered later by Susannah Dean.

Roland also notes that Jake strongly resembles Alain, another gunslinger, in his stable, reserved personality and talent with a psychic skill referred to as "the touch." Alain is described mostly by his time with Roland as a teen in Wizard and Glass.