Gamlen is a scion of the Amell family, who are nobility in Kirkwall. The Amells have lived for generations in an estate in Hightown. Gamlen inherited the Amell estate after his elder sister Leandra eloped with a Fereldan apostate named Malcolm Hawke. Though Gamlen spent the remainder of his parents' lives looking after them, he feels it was apparent he could never measure up to Leandra in their eyes.
When Leandra and her children flee from Lothering during the Fifth Blight, they make their way to Kirkwall and seek Gamlen's aid in entering the city. However, he has gambled away the family fortune, and lost the estate to Tevinter slavers. He now lives in Lowtown. When Hawke arrives to Kirkwall, the City Guard is preventing passage to all Fereldan refugees. In order to get his family in, he commits Hawke and his/her sibling to working with either a mercenary company or a smuggling group for a year.
When Hawke breaks into the Amell family estate and brings back his/her grandfather's will, it is revealed that Leandra and her children were to inherit the estate, while Gamlen was to live on a stipend, controlled only by his sister.
Three years have passed. Following Hawke's successful expedition to the Deep Roads, he/she had enough money to purchase the Amell estate. While Leandra and her eldest child have relocated to Hightown, Gamlen remains in his Lowtown hovel. He and Leandra have a weekly visit, however, and during "All That Remains," the fact that she misses this regular get-together is what alerts Gamlen and Hawke to Leandra's disappearance. Hawke's later investigation reveals that Leandra was kidnapped by a blood mage serial killer taking women who resembled his deceased wife; Hawke can optionally inform Gamlen of this, the result of which is that Gamlen blames his nephew/niece for not rescuing Leandra in time. Whether he knows the details of Leandra's death or not, Gamlen then voluntarily shoulders the burden of breaking the news to Bethany or Carver, noting that Hawke has enough on his/her mind. For the remainder of the act, Gamlen can be seen inside Hawke's estate.
Another three years have passed, and Hawke bears the title of Champion of Kirkwall. Gamlen himself remarks that he thought that the Amell line would die with him and is glad that Hawke pulled it out of the grave.In the quest "Gamlen's Greatest Treasure," Hawke discovers a note referencing the Gem of Keroshek, which Gamlen had wasted his life and family fortune trying to find. When Hawke follows the odd series of clues to their ultimate conclusion, he/she discovers that Gamlen has a daughter, Charade, of whose existence he has been completely unaware. Charade arranged the whole thing to see how far Gamlen would go to recover the jewel. Hawke may take the jewel for him/herself, or encourage Charade to meet her father and develop a relationship. If the latter occurs, Gamlen is pleased with his daughter and grateful to Hawke, though he also demands that Hawke refrain from meddling in his affairs from now on.
- (In the Blooming Rose) I won't mention this to your mother if you don't.
- (In the Blooming Rose) I'm just here for the medicinal benefits.
- (In Gamlen's House) So, you're moving up in the world. Got some coin to share with your favorite uncle?
- (In Gamlen's House) Single-handedly saved the city from the heathens, huh? The viscount should have paid me a finder's fee.
- (In Gamlen's House) So, you're into elves, huh? I guess I don't have to ask which one of you's the girl. (to a male Hawke if Fenris is romanced)
- (In Gamlen's House) So, you're into elves, huh? It takes all kinds. (to a female Hawke if Fenris is romanced)
- (In Gamlen's House) So, I've heard you let that apostate live at your place. I guess I don't have to ask which one of you's the girl. (to a male Hawke if Anders is romanced)
- (In Gamlen's House) I hear you moved that apostate boy into your house. You really are your mother's daughter. (to a female Hawke if Anders is romanced)
- (In Gamlen's House) So, I hear that you've been slipping it to that pirate slut from the Hanged Man. What's that like? Two women? I've always wondered... (to a female Hawke if Isabela is romanced)
- (In Gamlen's House) So, I hear that you've been slipping it to that pirate slut from the Hanged Man. The bitch turned me down flat. (to a male Hawke if Isabela is romanced)
- Like the Hawke twins and Leandra, Gamlen can have an alternate appearance depending on the face preset the player chooses during the character creation. His hairstyle will change, but will always be grey.
- It remains unclear what becomes of Gamlen after the beginning of the mage/templar war. The section of Lowtown where he lives is gated off when Hawke passes through en route to the Docks, thus making it impossible to speak with him.
- During a conversation with Anders in his Questioning Beliefs (Anders Act 2), a Sarcastic/Charming Hawke may jokingly question "Why do none of my friends ever just want to be the best Wallop player in Lowtown?" Later, during the Act 3 quest Gamlen's Greatest Treasure, it is revealed that Gamlen keeps his old Wallop Mallet on the wall in his house, and he explains that he used to play as a boy. He also asserts that playing Wallop was the "Last time I was any good at anything." This may indicate that Gamlen himself is actually the best Wallop player in Lowtown.