Dimension 20 is CollegeHumor's tabletop RPG show that runs Dungeons & Dragons 5e campaigns, of which there are:

Title card

Brennan Lee Mulligan DMs for all the campaigns and the main cast includes Lou Wilson, Siobhan Thompson, Zac Oyama, Emily Axford, Brian "Murph" Murphy, and Ally Beardsley.

Guest players include:

  • Matt Mercer (Escape from the Bloodkeep and Pirates of Leviathan)
  • Erika Ishii (Escape from the Bloodkeep)
  • Justin McElroy (Tiny Heist)
  • Travis McElroy (Tiny Heist)
  • Carlos Luna (Pirates of Leviathan)
  • Marisha Ray (Pirates of Leviathan)

There were also two oneshot Fantasy High live events in Brooklyn and Austin which invited guest players Brian David Gilbert and Griffin McElroy respectively. A live Fantasy High oneshot was broadcast in October 2020 featuring half of the cast (Lou, Zac, and Murph).

Tropes used in Dimension 20 include:


  • Born Unlucky: Downplayed. Murph commonly rolls natural ones or otherwise low numbers when performing skill checks or saving throws.
  • It Amused Me: Emily sometimes baffles everyone (including Brennan) with her character choices. Examples include the Sexy Rat and Hilda Hilda incidents.
  • Million-to-One Chance: When a pivotal story moment is determined by a die roll, Ally is almost guaranteed to roll a natural 20.