Tékumel (aka The Empire of the Petal Throne or Tsolyáni Empire) is not a TSR World.
[Phillip] Muhammad Abd-al-Rahman [M.A.R.] Barker (11/03/30 - Present) was a Professor of Urdu and South Asian Studies at the University of Minnesota during the period when David Arneson, Gary Gygax and a handful of others were developing the first role-playing games in the Twin Cities, MN and Lake Geneva, WI.
Barker tapped into this tradition and the setting he had developed from his childhood fantasies to further explore and develop Tékumel. His "Thursday Night Groups" [consisting of Bob Alberti, Victor Raymond, Carl Brodt, Brett Slocum, Alan Musielewicz] were amongst the first roleplaying sessions anywhere and provided what was, at the time, an unusually detailed week-by-week development of the setting, and still continue.
In 1975, Tactical Studies Rules, Inc., the publishers of Dungeons & Dragons, published Barker's roleplaying game and setting as a standalone game [based on rules he created in 1974] under the title of The Empire of the Petal Throne, rather than as a "supplement" to the original D&D rules. Bringing a level of detail and quality to the concept of a campaign setting which had previously been unknown in the nascent RPG industry's publications it could be considered a qualitative reimagining, less heavily entrenched in the tactical mass-combat, wargaming roots of D&D.
The game was the subject of articles in early issues of Dragon Magazine, but factors including inconsistent support from TSR led to its decline in popularity. Over the subsequent thirty years several new games based on the Tékumel setting were published, but to date none have met with commercial success. While published as fantasy, the game is sometimes classified as science fantasy or, debatably, as science fiction.
TSR was locked into a deal that made the financial end of the game unpalatable to them.
- They had agreed to pay a "finders fee" on sales in addition to royalties.
- They had agreed to certain expensive overrides, such as the famous map.
At the end of the day that made the product twice as expensive, or more, as anything else and far less profitable. In addition, Barker was perceived as having a very strong ego. Whether the perception is fair or not, it would later plague Barker's acceptance and reputation.
In 2008, Barker founded the Tékumel Foundation along with many of his long-time players, to preserve and manage rights relating to his creations in future.
He and his wife, currently reside in Minneapolis, MN.