One Shot Wikia

System Mastery is a both a property and podcast with two hosts, Jef and Jon. The series proper, System Mastery, revolves around Jef and Jon reading old RPG books and discussing the settings and mechanics interspersed with a liberal amount of anecdotes and tangential discussions.

According to unconfirmed reports, Jef and Jon are two separate individuals. This is commonly regarded to be a false claim however due to their indistinguishable voices on-mic. Therefore, the truth of the matter is that the podcast is actually hosted by a single man and his sock puppet.

Movie Mastery

"WE watch the movies that YOU recommend"

Movie Mastery is a show wherein Jef and Jon review randomly rolled user curated films. Human nature being what it is, the viewers have managed to collect the true dregs of the Hollywood film industry out of mouldering Blockbuster storage facilities. Once a month, the pair records an "In Theatres Now" show decided on each month by user poll. Again, the fickle mob shows no mercy, once sending the pair to see My Little Pony, this episode featured guest James D'Amato known bronie.

Expounded Universe

Expounded Universe is the Star Wars Expanded Universe Novel Discussion Podcast hosted unsurprisingly by Jef and Jon, or occasionally Jon and Jef. The pair show true courage in the face of misery as they trudge through the malodorous leaving of the EU.

Title Author Episodes
Shadows of the Empire Steve Perry 1-14
The Crystal Star Vonda N. McIntyre 15-28
Tales from the Mos Eisley Cantina Various, Edited by Kevin J. Anderson 29-44
The Courtship of Princess Leia Dave Wolverton 45-58
Red Harvest Joe Schreiber 59-71
Planet of Twilight Barbra Hambly 72-84
Vector Prime R. A. Salvatore 85-97
Star Trek TNG: X-Men Crossover

Planet X*

Micheal J. Friedman 98-110
Crucible Troy Denning 111-124
Han Solo At Stars End Brian Daley 125-130
The Glove of Darth Vader Paul Davids and Hollace Davids 131-132
Galaxy of Fear John Whitman 133-137
Jedi Search Kevin J. Anderson 138-148
Ruins of Dantooine Haden Blackman and Voronica Whitney-Robinson 149-157
Maul Lockdown Joe Schreiber 158-174
Supernatural: Witch's Canyon* Jeff Mariotte 175-185
Coruscant Nights Michael Reaves 186-198
I, Jedi ** Michael A. Stackpole 199-213

*Jef mistakenly allowed Jon to chose the book for Seasons 8, and 16. Goddammit Jon. Season is known as X-pounded Universe and covers an Xmen/Star Trek Crossover novel. Season 16 dives into the Supernatural universe and the boys cover Witch's Canyon. Be sure to check out the mid season interstitial, as Jon was out of town, Jef and Special Guest Claire cover Supernatural Fanfic.

** Anecdotally, all episodes from this season follow the book's naming scheme. e.g. I, Died Offscreen/I, Sometric Exercise/Aye, Pirate

Patreon content exists for this show in the from of a Wookiepedia deep dive wherein the dynamic duo compete to pull out the wackiest of business from the depths of Wookiepedia.


Afterthought was originally a loosely Q&A based show, although in reality it was just an excuse for Jef and Jon to talk about stuff for a bit. The show was eventually retired for a time before returning as a Patreon Exclusive.

System Mastery's Memes

The System Mastery duo has improvised some iconic and rather unusual recurring segments, notably including:

  • Chester Baloonman
  • Donkey Talk
  • Helga the Punch Witch
  • Cheer Dudez