Wyatt grew up in Ithaca, NY. Wyatt had been playing role-playing games since the 1970s, beginning with the first Basic D&D set: "I remember prentending to be a wizard in my backyard before I picked up the basic set... I used the monster statistics in the D&D books to give us wizards something to fight in our primitive backyard live-action roleplaying game." Wyatt was a religion major while attending Oberlin. He graduated from Oberlin College in 1990 with a Bachelor of Arts in Religion, and received a Master of Divinity from Union Theological Seminary in New York City, in 1993. He served as the pastor of two small United Methodist churches for two-and-a-half years, in southeastern Ohio from 1994 to 1996.

At that point, Wyatt decided to change his career path: "While I was in the ministry, I started submitting adventures to Dungeon Magazine... I found that my D&D work was a source of freedom and energy when ministry was more life-draining for me. When I started getting adventures and articles accepted, it was so exciting that it became clear that D&D would never again be just a hobby for me." In 1996, Wyatt began writing material for Dragon Magazine as well, starting with material for TSR's Masque of the Red Death setting, and then moved to Wisconsin in hopes of getting a job at TSR. He also lived in California before moving to Washington in 2000.

Wyatt began producing freelance work for roleplaying games such as West End's Hercules and Xena, although he felt that "D&D has always been my one true love in the gaming world... despite junior high flings with other game systems." He continued to have material published in Dragon and Dungeon, and Wizards of the Coast ultimately hired him in January 2000 to work on the D&D game; his first assignment was Monsters of Faerûn, of which he wrote two-thirds. His other early works for Wizards of the Coast included The Speaker in Dreams (a core adventure on the original Adventure Path, following The Sunless Citadel and The Forge of Fury), Defenders of the Faith, the monsters chapter in the Forgotten Realms Campaign Setting, and numerous articles in Dragon and Dungeon.

Honors

Wyatt received Origins Awards in 2003 for City of the Spider Queen and in 2005 for the Eberron Campaign Setting, which he co-authored with Bill Slavicsek and Keith Baker. His other notable works include Oriental Adventures (for which he won an ENnie Award in 2002), Draconomicon, and Magic of Incarnum.