Brennan Lee Mulligan

Brennan Lee Mulligan (born January 4, 1988) is an American comedian, actor, writer, and gamemaster. He often works with Dropout (formerly CollegeHumor) as a writer, performer, and producer. He is the creator and regular gamemaster for Dropout's actual play series Dimension 20 as well as the dungeon master for the first campaign of the creator-owned actual play podcast Worlds Beyond Number and the fourth campaign of the actual play web series Critical Role. He also wrote the superhero webcomic Strong Female Protagonist alongside artist Lee Knox Ostertag.

Early life Brennan Lee Mulligan was born on January 4, 1988, in New York He started attending The Wayfinder Experience, a live-action role-playing summer camp, spending much of his teenage years working as a lead story writer, performer, and camp counselor there. He was also homeschooled as a youth. In 2005, at 17 years old, Mulligan graduated from SUNY Ulster with an associate degree,

After graduating from university, Mulligan briefly worked as a camera PA on the set of Law & Order: Criminal Intent.

Career Writing

Mulligan and Lee Knox Ostertag co-created the webcomic Strong Female Protagonist, which was named one of io9's Best New and Short Webcomics of 2012.

In 2017, Mulligan joined CollegeHumor as a writer and fact-checker for Um, Actually: The Web Series. His audition tape included an impression of Tim Curry eating pizza, which allegedly got him the job. In 2018, CollegeHumor's streaming service Dropout launched Um, Actually as a game show, with Mulligan continuing to write for the show until 2020. Mulligan was also a writer for several scripted shows on Dropout, including the Star Wars parody space saga Troopers, and the mockumentary Gods of Food.

Performing In his twenties, he performed and taught He has also appeared on other Dropout shows such as Very Important People and Gastronauts.

In March 2026, Mulligan was a guest in "Dungeons & Dealers" for the television series Ted (2024); Mulligan helped rewrite the episode on set. That month, Mulligan also appeared on the new web series Jeopardy! YouTube Edition as a contestant.

Actual play

Since 2018,

Mulligan was the Dungeon Master for Exandria Unlimited: Calamity, a weekly, four-part actual play web series spin-off of Critical Role that premiered on May 26, 2022. He returned to Critical Role in 2024 as the Dungeon Master of the three-part special titled "Downfall" for the show's third campaign. Mulligan was then the Dungeon Master for Exandria Unlimited: Divergence which premiered on February 13, 2025.

In January 2023, it was announced that Mulligan, along with Erika Ishii, Aabria Iyengar, and Lou Wilson, would star in the creator-owned actual play podcast Worlds Beyond Number. The show launched on March 1, 2023, and quickly became one of the top 20 Patreon accounts in the world; Mulligan was the "inaugural game master". The first book of this campaign ran for four seasons with the finale airing in August 2025. The next campaign premiered in March 2026 with Iyengar as the game master and Mulligan shifting to a player role.

In August 2025, Critical Role announced that Mulligan would take over as Game Master from Matthew Mercer for their fourth campaign. The new campaign premiered on October 2, 2025 and features a new world "outside its usual Exandria setting". Rolling Stone stated that "the inclusion of Mulligan is huge, but not entirely surprising" given Mulligan's background as "a well-established Game Master" who created the "titanic success" Dimension 20 along with previous comments made by Mercer on eventually shifting "into a 'Professor X' role as a mentor to the next generation of storytellers rather than remaining the face of the brand in perpetuity". Also in October 2025, Mulligan was the Dungeon Master for the Endless Dungeon tour in Australia.

Accolades He has received an "Excellence in Performance Award" from the New York International Fringe Festival,

Personal life Mulligan is the godson of comics artist and writer Michael Kaluta. In November 2015, Mulligan was a contestant on the American version of Who Wants to Be a Millionaire and won after incorrectly answering the -question. By 2020, he lived in Los Angeles. On January21, 2021, Mulligan announced their engagement via Instagram. On January23, 2024, Brennan announced the birth of the couple's first child, a daughter, on the Patreon feed for the podcast Worlds Beyond Number. On March 31, 2026, on Jeopardy! YouTube Edition, Mulligan mentioned that he and Roland had another daughter.

Politically, Mulligan is a socialist. In August 2023, during the 2023 Writers Guild of America and SAG-AFTRA strikes, Mulligan led a Dungeons & Dragons-themed picket day at Universal Studios where the final boss was AMPTiamat. In 2026, Mulligan supported the Los Angeles DSA local election slate, hosting a Dungeons & Dragons'' game with the candidates which raised over $30,000.

Filmography

Television

Film

Web

Video games