Short answers, pulled from the story.
Mike Mearls co-led the design of Dungeons and Dragons Fifth Edition alongside Jeremy Crawford, and was a member of the Fourth Edition Flywheel design team. He also co-designed the Castle Ravenloft Board Game with Bill Slavicsek in 2010 and oversaw the launch of the 4th Edition Essentials line.
Mearls left the Wizards of the Coast tabletop RPG team in 2019. He moved to the Exploratory and Vision design teams for Magic: The Gathering before being laid off from Wizards of the Coast in December 2023, which he confirmed on Bluesky.
In May 2024, Mearls became Executive Producer of role-playing games at Chaosium. He left Chaosium in 2025 to work at Asmodee, though he continued contributing to some Chaosium projects including the new edition of RuneQuest.
Mearls was Co-Lead Designer for Dungeons and Dragons Fifth Edition, sharing that role with Jeremy Crawford. He held the position of senior manager for Dungeons and Dragons research and development in 2014 and later became the franchise's Creative Director by 2018.
Before joining Wizards in June 2005, Mearls wrote the adventure To Stand on Hallowed Ground for Fiery Dragon Productions in 2001, the Warhammer adventure Fear the Worst for Hogshead Publishing in 2002, and the game Iron Heroes for Malhavoc Press in 2005.
Mearls received a "special thanks" credit in Baldur's Gate 3, released in 2023. In a 2019 interview, he described his involvement as "story and system support".