Duncan was the Warden-Commander of the Fereldan Grey Wardens from sometime after 9:10 Dragon[note] until 9:30 Dragon. When Urthemiel rose and the Fifth Blight began, he recruited and mentored The Warden and Alistair shortly before the battle at Ostagar. He was among the first Wardens allowed to return to Ferelden after the actions of Sophia Dryden resulted in the order being exiled from the country. Subsequently, he faced suspicion and hostility in his search for new recruits.
Duncan was born in Highever but spent his childhood between Orlais and the Free Marches. His mother Tayana was from Rivain while his father Arryn was a Fereldan carpenter with Tevinter origins. After the death of his parents he was forced to become a thief to survive on the streets of Val Royeaux.
Growing up in Val Royeaux, Duncan witnessed a lot of death and disappearances. At one point, Duncan befriended a young female pickpocket who was attracted to him. One day she was struck by a nobleman's carriage begging for help but was ignored. Eventually she crawled into a nearby alleyway where she died from blood loss.
Duncan was known to seek out several quick dalliances at flophouses, encounters that ended quickly after the deed was done.
Barely more than a boy, Duncan broke into an inn room to rob it, and was confronted by his victim while attempting to steal a ring. The man refused to give in, even with a knife to his throat, and they fought; in the struggle, Duncan unintentionally fatally wounded his victim. As the man lay dying, he thanked Duncan, to his shock and horror.
The chevaliers informed Duncan as he was arrested that the victim was a Grey Warden. When Commander Genevieve offered him a place among the Grey Wardens the night before his execution, he refused, thinking that a Grey Wardens' life must be horrible indeed to thank the one who murdered him. However, Genevieve showed up the next day during his execution and used the Right of Conscription in order to forcefully recruit him into the order. He was not entirely wrong at first; his fellow Wardens despised him, and in the months that followed, an unhappy Duncan attempted to run away several times, and continued to steal when the opportunity arose, a habit that saved his life in the Kinloch Hold some months later.
Eventually, the other Wardens began to accept him and revealed the truth to Duncan. His victim, Guy, had been betrothed to Genevieve, and the prize he refused to give up was intended to be her wedding ring. Duncan stopped running away and his unwavering loyalty to Genevieve in the last year of her life appeared, at least in part, to be have been born of guilt.
Six months after his induction into the order, Duncan was a member of the Grey Warden attachment led by Genevieve from Orlais on a mission to find the missing Warden Bregan, Genevieve's brother and the previous Warden-Commander of Orlais. Genevieve charges him with a grim duty: protect their guide in the Deep Roads, King Maric Theirin, or, should the king learn information detrimental to the Order, kill him. As Commander Genevieve put it, "the Grey Wardens protect all of Thedas, not simply one small nation." Instead Duncan befriended Maric, and his actions were instrumental to Maric's survival.
During their mission to ascertain the fate of Bregan, Genevieve's brother who had left on his calling, Duncan, Maric and the other Grey Wardens were confronted by a demon and trapped in the Fade. While attempting to rescue Genevieve from her dream in the Fade, Duncan was confronted with the happy life she had wanted to lead had her fiancé lived. When Duncan tried to convince her to leave, she directed the full brunt of her grief and fury over the boy's part in Guy's death at him. She bitterly told Duncan she thought the fact he survived his Joining was a cruel joke played on her by the Maker. She had wished him dead, and so had forced him into the Joining in the hope he would die after getting a taste of what the Wardens went through to protect scum like him, only to be stuck with him. Duncan was stricken at first until he surmised that if she had truly wanted him gone, she could have left him to his execution, or transferred him to another outpost in the order. He confronted her with the truth, and reluctantly Genevieve left with him, escaping the Fade.
After they are captured and Genevieve and Utha join Bregan to side with the Architect, Duncan frees Maric and Fiona and together they flee from Kul-Baras while Kell ap Morgan along with Hafter stay behind to help their escape. Eventually they reach the surface but are captured by First Enchanter Remille and being brought to Kinloch Hold. When the rogue Wardens and the Architect turn against each other, Duncan takes the opportunity to kill Remille using the ebony-black dagger he had stolen from him earlier, while Loghain Mac Tir liberates the tower.Later, Duncan is named as second in command of the Ferelden Grey Wardens, serving under Warden-Commander Polara and swears to watch over Fiona and Maric's son.
Duncan appears in every Origin story, searching for a recruit to join the Grey Wardens to aid against the growing threat of the Fifth Blight. He will recruit the Warden either voluntarily or through conscription, and is usually available to answer questions about the Grey Wardens and the darkspawn horde massing in the Korcari Wilds during the origin story.
- Human Noble Origin: Duncan arrives at the Cousland's estate looking for a potential recruit. The one petitioned for this was Ser Gilmore, but it is later revealed that the Human Noble Warden was always Duncan's first choice.
- Mage Origin: Duncan arrives at the Circle Tower to recruit additional mages for King Cailan's army, and is introduced to the Magi Warden by First Enchanter Irving. After Jowan escapes using blood magic, Duncan reveals that he was also searching for Warden recruits and forces Knight-Commander Greagoir to release them into his custody.
- City Elf Origin: Duncan arrives in the Elven Alienage, in hopes of recruiting the son/daughter of Adaia. When Vaughan Kendells kidnaps the women from the wedding ceremony, he indirectly aids Soris and male Warden/Nelaros by supplying a sword. After the City Elf Warden is arrested for killing Vaughan (or if you didn't, arrested for robbing him), Duncan steps in and invokes the Right of Conscription to save them from imprisonment/execution.
- Dalish Elf Origin: After Tamlen and the Dalish Elf Warden come into contact with the mirror which Duncan believes to be Tevinter in origin, Duncan rescues an unconscious Warden and brings them to the Dalish camp. He returns to the ruins to investigate the darkspawn taint, and explains to the Dalish Elf Warden and Merrill that Tamlen is most likely dead by now and the Warden has been corrupted by the mirror. After destroying the artifact, he discusses the affliction with Marethari and explains that only the Joining ritual can save the Dalish Elf Warden from succumbing to the taint.
- Dwarf Noble Origin: Duncan arrives in Orzammar to witness the Proving being held in the Dwarven Noble Warden's honor. Later, when the Warden is exiled, they find Duncan in the Deep Roads whereupon they are recruited and saved from death in the darkspawn filled tunnels. Unlike the other origins, he can be seen with two other Grey Wardens.
- Dwarf Commoner Origin: Like the Dwarf Noble origin, Duncan arrives in Orzammar to witness a Proving. There he watches the Dwarf Commoner Warden win the Proving under the disguise of being another fighter. When the Warden escapes from prison, Duncan intervenes and recruits the Warden before the authorities can execute them.
After Duncan recruits the Warden, the two travel to the ruins of Ostagar to take part in the upcoming battle with the King's army against the darkspawn. After receiving a royal welcome from King Cailan himself, Duncan instructs the Warden to seek out Alistair and the two other recruits to prepare for the Joining ritual. He tasks Alistair and the recruits with heading into the Korcari Wilds to obtain three vials of darkspawn blood for the ritual, as well as recovering old treaties from a Grey Warden cache in the wilds. During this time you can steal from him various items including runes, Greater Nature Salve and poultices.
Shortly before the battle, Duncan oversees the Joining ceremony for the new recruits. Daveth does not survive the ritual, whereupon Ser Jory panics and attempts to flee, causing Duncan to kill him. The Warden is the only recruit to survive the Joining, and is informed that Cailan requested their presence at the upcoming strategy meeting.
At a war council soon after, King Cailan orders Alistair and the Warden to light the beacon on top of the Tower of Ishal, signaling for Loghain and his army to flank the engaged darkspawn horde. Loghain, however, decides to withdraw his forces after seeing the signal. The royal army and the Grey Wardens, now hopelessly outnumbered, lose the battle. King Cailan is crushed to death by an ogre that Duncan slays, falling himself under the next darkspawn rush. Though Duncan is confirmed to be dead, his actual death is not witnessed, nor is his body found if the Warden returns to Ostagar.
In a discussion later in the game, Alistair reveals that Duncan had recently started to experience the "nightmares"—intense visions of the darkspawn that begin shortly after the Joining and fall away gradually—again, suggesting that the taint was starting to claim him and he did not have much time left.Late in the game—during the Landsmeet—the party can find Duncan's Shield in a Grey Warden cache in Denerim. The shield is a gift for Alistair as well as a powerful armor piece, one of the best in the game. In the Return to Ostagar DLC the party can reclaim Duncan's Sword and Duncan's Dagger from the ruins of Ostagar.
- City Elf Origin (conditional)
- Dalish Elf Origin (conditional)
- Dwarf Commoner Origin (conditional)
- Dwarf Noble Origin (conditional)
- Human Noble Origin (conditional)
- Magi Origin (conditional)
- Joining the Grey Wardens
- Tainted Blood
- The Grey Wardens' Cache
- After the Joining
- The Tower of Ishal
Dragon Age: Origins
- (to a City Elf Warden) "Surely it has not escaped your notice that I am both armed and armored. Any fight between us would be rather one-sided."
- "I sometimes wonder if the Chantry's many laws regarding magic are even necessary. Darkspawn are a greater threat than blood mages, even abominations. It takes decades for the world to recover from a Blight."
- "Be careful what you wish for. Power is treacherous. I have seen many people--great leaders--consumed by it."
- "From here, you two are on your own. Remember, you are both Grey Wardens. I expect you to be worthy of that title."
- Duncan: "You're talking to the wrong Grey Warden. All I know is that they spent all their time searching for the Old Gods."
- King Maric: "That's it? Nothing else? They must be boring at parties."
- Duncan: "That's pretty much it. They don't think, exactly."
- Codex entry: Duncan states that his father was from Tevinter and his mother from the Anderfels, while Dragon Age: The Calling describes him as half-Fereldan, half-Rivaini. David Gaider confirmed that the latter version is the correct one.
- Codex entry: Fiona's statement that Duncan was made Warden-Commander in 9:10 Dragon is inconsistent with the timeline presented in Dragon Age: The Calling.
- In BioWare's character file for him, his appearance is described as: "Bearded, muscular, hair graying at the temples. Has a noble bearing."
- Duncan is the first shared similarity between all of the origins.
- Duncan makes a small cameo in Dragon Age: Inquisition in the form of the nightmare difficulty tarot card before character creation. 
- Duncan's set of armor is unique—he is the only character using such an armor model.
- If a male Dwarf Noble completes the Of Noble Birth quest, he has the opportunity to name his son Duncan.
- Though Duncan is confirmed to be dead, his body is never found at Ostagar, though his weapons will be found impaled in the ogre he had slain before falling at the hands of the darkspawn.
- Duncan will have new dialogue options if you try to pickpocket him and fail.
- In the cutscene where Duncan kills the ogre he uses two Crow Daggers instead of Duncan's Sword and Duncan's Dagger.
- It's possible to steal a master or grandmaster hale, silverite or cold iron rune or clear grade small or large crystal from him at Ostagar, twice, one before going to the Korcari Wilds and one after.
- Despite wielding two weapons in The Calling, a shield belonging to Duncan can be found in the Grey Warden Vault located in Denerim. It is unknown if he actually used it in battle or not.
- The general similarity between aspects of Duncan's armor and that of Isabela appears to be indicative of a Rivaini style of armor.
- His personal background as given in the toolset states that he is the bastard son of a noble family that does not recognize him, and that this is the reason he took pity on Alistair.
- Dragon Age: The Calling, p. 272. Duncan's mother is pregnant in Duncan's dream.
- Dragon Age: The World of Thedas, vol. 2, p. 77
- Gaider, David. "DAO novels and game: some inconsistencies?" Bioware Social Network. Retrieved 28 March, 2012.
- Dragon Age: Origins Resource File: duncan.chr
- Mike Laidlaw Twitter. https://twitter.com/Mike_Laidlaw/status/394703081457209344/
- BioWare Wiki Duncan (archived)