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 sold the Amell estate to Tevinter slavers. He now lives in Lowtown. When Hawke arrives to Kirkwall, the Kirkwall City Guard is denying access to all Fereldan refugees. In order to get his family in, Gameln commits Hawke and their sibling to working with either a mercenary company or a smuggling group for a year. During which time the Hawke family live at Gamlen's House in Lowtown.
When Hawke breaks into the Amell family estate and brings back their 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.
By 9:34 Dragon, following Hawke's successful expedition to the Deep Roads, Hawke had enough money to buy back the Amell estate. While Leandra and her eldest child have relocated to their ancestral home in Hightown, Gamlen remains in his Lowtown hovel. He and Leandra have a standing weekly visit, however, when Leandra vanishes and fails to appear for their regular get-together, Gamlen goes to Hightown to alert Hawke to Leandra's disappearance. Hawke's later investigation reveals that Leandra was kidnapped by a blood mage serial killer, Quentin, taking women who resembled his deceased wife. Although Quentin is killed, Leandra perishes as well. Hawke can optionally inform Gamlen of Quentin's plan, the result of which is that Gamlen lashes out at Hawke 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 their mind.
By 9:37 Dragon, 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.
Hawke discovers a note referencing the Gem of Keroshek, a rare jewel which Gamlen had wasted a good portion of his life and family fortune trying to find. When Hawke follows the odd series of clues to their ultimate conclusion, Hawke discovers that Gamlen has a daughter, Charade, of whose existence he is 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, remarking that Malcolm Hawke must have been a decent individual if he raised a child like Hawke, though he also reiterates his demand that Hawke refrain from meddling in his affairs from now on.
If Bethany/Carver did not survive the Deep Roads Expedition, Gamlen speaks to Hawke regarding Malcolm's actions. He then recounts how Malcolm and Leandra met, and how he distracted their father, Aristide Amell, to allow the two to talk.
- (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?
- 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.
- 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.