Cortex System

The Cortex System is a collection of related roleplaying games. Its most recent iteration, "Cortex Prime," was designed by Cam Banks and published by Fandom Tabletop. Prior versions appeared in the licensed roleplaying games published by Margaret Weis Productions, where it was used as the house system. Cortex is an adaptable game system focusing on characterization and story development.
Game mechanics.
Cortex is an extensible and modifiable game, but a few elements are common to all games. Characters are described with a number of trait sets, such as attributes, skills, relationships, or powers. Each trait within each set is rated with a die size. For example, a strong but unintelligent character might have Brawn d10 and Brains d4. When rolling dice, players select one trait from each set and roll their dice together as a pool. Dice that roll 1 are 'hitches', and represent something going wrong in the attempt. The highest two die results are added together for the player character's effective total. Another die not used in the total is selected as the effect die, the size of which determines the magnitude of the die roll's impact.
Players also have access to a limited pool of 'plot point' tokens, which can be spent in a number of ways. Prominent among these is to roll more than one die from a single trait set, or to add additional die results to the total.
Most Cortex games include "Distinctions" as one of the trait sets, which describe what makes the character distinctive. These traits are rolled as a d8 when they are beneficial. When the distinction hinders the character, however, it is rolled as a d4, and the player earns a plot point.
History.
The earliest predecessor to Cortex was the Sovereign Stone Game System, produced by Sovereign Press, Inc and published by Corsair Publishing, based on the "Sovereign Stone" novels. The game was written by Larry Elmore and Don Perrin.
Cortex Classic.
In 2004, the rights to Sovereign Stone was transferred to Margaret Weis Productions, where the system was used for the Serenity Role Playing Game, published in 2005. The game system was used, with minor amendments, for Battlestar Galactica Role Playing Game in 2007 and Supernatural Role Playing Game in 2009. The game was released as a standalone, generic roleplaying game in 2008 as "Cortex Role Playing Game System".
Cortex Plus.
In 2009, Cortex development was passed to Cam Banks, who refined it into "Cortex Plus" by introducing its roll-and-keep system and streamlining all ranked stats to use die sizes that could be rolled in various conflicts. Cortex Plus saw its debut in 2010 with Smallville Roleplaying Game and . Both games were developed concurrently, with design notes passed between writing teams, but each game featured unique variations on the basic Plus engine.
The next round of development saw Banks create Marvel Heroic Roleplaying, published in 2012. This game focused on action sequences and fights. The core game was originally slated to be followed by a long series of supplements, each focusing on a different historical period of Marvel's fictional history. However, in 2013, Margaret Weis Productions announced that it would not be renewing its Marvel license, and the game went out of print.
The "Cortex Plus Hackers Guide," an anthology compilation of many different 'hacks' of Cortex Plus, was initiated in January 2013. Without the licenses for the three existing games, the Hacker's Guide presented three 'flavors' of Cortex Plus: drama, action, and heroic. Monica Valentinelli then developed the Firefly Role-Playing Game, published in 2014. "Firefly" was primarily based on the "Leverage" rule set.
Cortex Prime.
On November 1, 2016, Margaret Weis Productions released a statement announcing that Cam Banks and his new design studio Magic Vacuum had licensed the Cortex system and would be "taking over the design, development, and publishing of games based on these rules... for 2017 and beyond," coinciding with "Margaret’s retirement from RPG development to focus on her current novel and film projects."
Banks then set out to normalize the four games of the Cortex Plus era as well as the preceding four Classic games into a single, unified system. This iteration, Cortex Prime, was funded via Kickstarter in April of 2017. Prime discards the 'drama, action, and heroic' flavors of Plus and instead offers an extensibly modular system that can be custom-built for vastly different play experiences. As part of the Kickstarter stretch goals, five volumes of "spotlight" mini settings, compiled by 22 authors, were also planned and funded.
In September 2019, Fandom Tabletop acquired the rights to Cortex from MWP and hired Cam Banks as their new Cortex Creative Director. Fandom intends to publish the "Cortex Game Handbook" in 2020. In 2021, Fandom plans to publish the five volumes of spotlights, as well as two licensed game settings: "Tales of Xadia: The Dragon Prince Roleplaying Game" based on The Dragon Prince television show, and "Legends of Grayskull: The Masters of the Universe Roleplaying Game" based on The Masters of the Universe franchise.