Wizards of the Coast

After working as the Policy Director for Organized Play for the Magic: The Gathering game, Carl became a member of the Wizards of the Coast R&D team, designing adventures and modules for the Dungeons & Dragons game: "Both careers have their rewards... but I've wanted to be involved in RPG design since I was fourteen - after all, I still remember rolling my first d20. So I couldn't pass up the opportunity to make the switch."^[1] When the D&D third edition was released in 2000, Carl was the designer chosen to begin the process of adding detail to the character classes in the supplement Sword and Fist (2001); he felt that this book "is important because it establishes the model for those that will follow it".^[1]

World of Darkness

Carl was the CEO of By Night Studios from 2010 to 2018; By Night Studios is the official licensed publisher of new Mind’s Eye Theatre products for White Wolf’s World of Darkness setting.^[2][3] In 2019, he transitioned to the publisher's advisory board.^[4]

In early 2018, Carl was a game producer on the 5th edition of Vampire: The Masquerade (part of the World of Darkness series)^[5] and an "executive vice president of community" at White Wolf,^[6] a subsidiary of Paradox Interactive. Later in 2018, Paradox dissolved White Wolf as an independent entity.^[7][8] In 2019, the 5th edition of Vampire: The Masquerade won the Origins Award for Best Roleplaying Game of the Year and won the Origins Fan Favorite Award.^[9]

Since 2019, Carl has been the Brand Marketing Manager of Paradox's World of Darkness.^[10][11] He also been the storyteller of multiple canon World of Darkness actual play web series including L.A. by Night,^[12] and Seattle By Night.^[13] Carl is the storyteller for the NY by Night web series which is a sequel to L.A. by Night.^[14] Em Friedman, for Polygon, stated that L.A. by Night "survived Geek & Sundry's decline [...] in no small part to the masterful work of storyteller and series creator Jason Carl".^[15] On NY by Night, Friedman commented that "Carl has a deft hand for scene-setting, creating lyric love letters to real-world locations both famous and obscure" and that "Carl and the players have always been innovators, working toward high production values, costuming, and even creating prerecorded interstitial scenes".^[15]