Oathbound: Plains of Penance is the first domain sourcebook for Oathbound: Domains of the Forge, and details wild and abundant grasslands and vast cities of Penance. Chapters provide an overview of the plains, their inhabitants, the ecology, the druids, cities, northern oceans, the wilderness, an adventure for 4 to 6 characters of 8th to 10th level assigned to scout a dangerous forest, and three appendixes of new monsters, items, and spells.

From the back cover:

Beyond the most populous city of the Forge lies a vast, uncontrolled expanse of rolling grasslands, scattered crags, and light woods. In strong contrast to the rest of the world, where nature stands in opposition to intelligent life, the bountiful land here provides a lush wealth of resources upon which the great cities have come to depend. Powerful forces vie for control over this abundant domain, as ruthless bloodlords of the cities clash against the deep-rooted druids of the wilds, hardened armies from the west, and even mysterious visitors from the depths of the northern oceans.

Within Plains of Penance you'll find:

• 5 new player-character races
  
• 5 new prestige races
  
• 2 new prestige classes (Artificer and Disjoiner)
  
• New magic items, monsters, spells, and weapons
  

Plains of Penance requires the use of the Dungeons & Dragons Player's Handbook, Third Edition, published by Wizards of the Coast. The core campaign book, Oathbound: Domains of the Forge, is also highly recommended.