Gaider began his professional life providing services at restaurants and hotels, while game designing was a side hobby to him. A friend of Gaider, Kalvin, happened to be working at BioWare and suggested to Ray Muzyka and Greg Zeschuk that Gaider be given a recently opened position in the design department. Gaider got the job and, as his first assignment, was given the task of providing designs for Baldur's Gate 2. He wrote the characters HK-47, Jolee Bindo and Carth Onasi for Star Wars: Knights of the Old Republic, and was the lead writer for Neverwinter Nights: Hordes of the Underdark, on which he wrote both Deekin and Valen Shadowbreath. Gaider was set as lead writer on Baldur's Gate's spiritual successor, Dragon Age: Origins, creating the world of Thedas in which the game is set. He wrote the characters of Zevran, Alistair, Cailan, Morrigan, Shale and Duncan along with the quests "Nature of the Beast" and "Redcliffe". After the success of Origins, Gaider also wrote its book prequels, The Stolen Throne and The Calling. Afterwards, Gaider wrote for Dragon Age II, where he had a major contribution to the plot, creating the characters Cassandra Pentaghast, Fenris, and Meredith, and wrote the follow-up novel, Asunder, which was released on 20 December 2011. In 2012, Gaider released Dragon Age: The Silent Grove, a comic series published by Dark Horse Comics. Aside from design and writing, Gaider often posts messages at BioWare's community folder.