Matthew Dixon (aka Mattrim of Amber) was a Doomer from Sherwood Park, Alberta, Canada known for creating intricate deathmatch PWADs with medieval brick buildings. His Amber series, released in 1996, caught the attention of Anthony "Adelusion" Czerwonka, leading Matt to be added to the GothicDM team alongside local friend Daniel "The Waffle King" Twomey. Each successive map created by Matt became more focused on increasing texturing details. His Gothic 99 contributions are seen by some as the most excessively detailed Doom II levels ever created.
Aside from designing levels, Matt was known to playtest Doom projects, including The Darkening Episode 2, Richard Wiles' Crusades, and Malcolm Sailor's Chord series. His quality assurance work for GothicDM 2 is seen as the epitome for PWADs that work within Vanilla Doom.
For Doomworld, he wrote The /oldstuff Chronicles, judged the 10 Sectors contest, and took part in the article, Doom 3: The Doomers Speak Out. He was interviewed by SFGate.com after the Columbine High School Massacre regarding correlations between video games and school violence. He also contributed level reviews for Martin "Cocoon" Friberg's DooMster web site.
- Enjoys paying homage to MAP01: Entryway (Doom II) (see: Amber Series 01 and Gothic 99 MAP01) and to his own past work (see: Gothic 99 MAP01 and Amber Series 06).
- Collaborated with Daniel "The Waffle King" Twomey on 4 maps across the GothicDM series.
- Provided help with texturing and detailing SlaughterDM's MAP04, which was made by fellow GothicDM members Anthony "Adelusion" Czerwonka and Iikka "Fingers" Keränen.