A native Fereldan, born and bred in Highever, he joined the Wardens at the same time as Duncan. Having lost contact with Ferelden's Grey Wardens, Riordan was sent to Denerim to find out what had become of them; however he was captured and taken prisoner by Rendon Howe after Howe had invited him with an offer of parley and subsequently drugged him.
Riordan is first encountered in Arl Howe's dungeon. As the Warden enters the dungeon, Riordan takes advantage of the distraction this provides to snap his guard's neck through the bars of his cell. If Alistair is in the active party, he will recognize Riordan as one of the Wardens present at his Joining.
The Warden can speak briefly with Riordan, who will explain that he is a Grey Warden from Orlais who came to Ferelden to find out what happened at Ostagar. Orlais had originally sent a large contingent of Grey Wardens and chevaliers, but were turned back at the border of Ferelden. It was decided that a single person would make it into the country more easily than a group, and Riordan was sent because of his familiarity with Ferelden. However, he was captured, imprisoned and tortured.
Riordan will then leave, saying he would not be helpful in his current condition and is in need of a healer. He can be found afterwards in Arl Eamon's room in the Arl of Redcliffe's Estate. The Warden can speak to him there about the Grey Wardens and Duncan. He will also mention the Grey Warden Vault, which contains high quality equipment and other items, and will mark it on the Warden's map.
The night before the Battle of Denerim, Riordan explains to the Warden and either Alistair or the Secret Companion, why the Grey Wardens bear the burden of slaying the archdemon: the Archdemon's soul will seek out the taint in the nearest darkspawn, reshaping it into the fearsome form of a dragon, essentially making itself immortal. However, if the nearest tainted being already contains a soul--such as a Grey Warden--the two souls cannot coexist in the same body, destroying each other. Being the most senior Grey Warden, Riordan will attempt to take this burden onto himself, but warns that it is a duty that the three of them must undertake.During the Final Battle, Riordan assists the Warden in taking Denerim's gates. After clearing the gates of darkspawn, Riordan tells the Warden that they must split up and find the Archdemon, citing that three Wardens would be too obvious and that he will go alone. Afterwards, he is shown dispatching darkspawn before sensing the Archdemon flying nearby, chasing it once he spots it. Riordan jumps off a tower onto its back, stabbing it several times. After some twists and turns, however, the Archdemon manages to kill Riordan by throwing him off at a great height, but not before Riordan has inflicted a serious wound to its wing, forcing it to land on top of Fort Drakon for the remaining Wardens to finish off.
- It is possible to steal around 5 from him in Redcliffe Castle or a Master Hale or Silverite rune instead; however, it will likely require repeated attempts (save & reload) to do so.
- "Be firm in your beliefs, protect people from their own ignorance, and be as loyal as you can to your brothers, even knowing that you'll share their deaths."
- "The Joining binds us to the darkspawn. You know this. If you were to forswear your oath and flee today, you'd find yourself in the Deep Roads or the Blight-lands, given time."
- "Nothing you have done has prepared you for what you face now."
- Riordan is described in some detail in the toolset. He is a serious man, and a soldier; one who is accustomed to discipline and used to being in a position of leadership. If circumstances were different, he would be the center of this story, not the Warden, and the one leading the charge against the forces of evil. He is a hero, and one who is determined to do his duty no matter the consequences. In order to stop the darkspawn, some things must be sacrificed, even lives -- but he would prefer to give his own life before he sacrifices someone else's.