The Scarlet Brotherhood is a regional sourcebook for the Greyhawk

Greyhawk

Greyhawk, also known as the World of Greyhawk, is a fictional world designed as a campaign setting for the Dungeons & Dragons fantasy roleplaying game...

 campaign setting

Campaign setting

A campaign setting is usually a fictional world which serves as a setting for a role-playing game or wargame campaign. A campaign is a series of individual adventures, and a campaign setting is the world in which such adventures and campaigns take place...

 for the Dungeons & Dragons

Dungeons & Dragons

Dungeons & Dragons is a fantasy role-playing game originally designed by Gary Gygax and Dave Arneson, and first published in 1974 by Tactical Studies Rules, Inc. . The game has been published by Wizards of the Coast since 1997...

fantasy

Fantasy

Fantasy is a genre of fiction that commonly uses magic and other supernatural phenomena as a primary element of plot, theme, or setting. Many works within the genre take place in imaginary worlds where magic is common...

 role-playing game

Role-playing game

A role-playing game is a game in which players assume the roles of characters in a fictional setting. Players take responsibility for acting out these roles within a narrative, either through literal acting, or through a process of structured decision-making or character development...

. The sourcebook was written by Sean K. Reynolds

Sean K. Reynolds

Sean K Reynolds is a professional game designer who has worked on and co-written a number of D&D supplements for Wizards of the Coast, as well as material for other companies. He does not put a period after his middle initial.-Background:...

, and published by TSR

TSR, Inc.

Blume and Gygax, the remaining owners, incorporated a new company called TSR Hobbies, Inc., with Blume and his father, Melvin Blume, owning the larger share. The former assets of the partnership were transferred to TSR Hobbies, Inc....

 in 1999 for 2nd edition Advanced Dungeons & Dragons. It detailed the Scarlet Brotherhood lands, the Tilvanot Peninsula, Hepmonaland

Hepmonaland

In the World of Greyhawk campaign setting for the Dungeons & Dragons roleplaying game, the continent of Hepmonaland is Southeast of the Flanaess. Hepmonaland was created as a in-game region where the Aztec culture is dominant and dinosaurs are very common monsters.Hepmonaland is the Suel and...

, and the Amedio Jungle.

The sourcebook was notable for being the first source on the Olman

Olman

The Olman are a fictional race of humans in the World of Greyhawk campaign setting for the Dungeons & Dragons fantasy roleplaying game. They inhabit the southern fringes of the Flanaess and are primarily a tribal people, though in the past they commanded a great empire...

 people since The Hidden Shrine of Tamoachan

The Hidden Shrine of Tamoachan

The Hidden Shrine of Tamoachan is an adventure module for the Dungeons & Dragons fantasy role-playing game, set in the World of Greyhawk campaign setting for use with the 1st edition Advanced Dungeons & Dragons rules...

and for detailing many new nations and realms south of the Flanaess

Flanaess

The Flanaess is the eastern part of the continent of Oerik, one of the four continents of the fictional world of Oerth in the World of Greyhawk campaign setting for the Dungeons & Dragons fantasy roleplaying game. The Flanaess has been the setting of dozens of adventures published between the 1970s...

 for the first time. The Touv

Touv

In the World of Greyhawk campaign setting for the Dungeons & Dragons roleplaying game, the Touv are one of the races of humans inhabiting Oerth. Found chiefly on the continent of Hepmonaland, the Touv people are known for warring with the Olman people in the northern jungles over the Olman Empire's...

 people and their pantheon were invented for this book. Several new monsters, including the Bredthrall, and many new plants and flora were created for this book as well.