In the Dungeons & Dragons fantasy role-playing game, the Beastlands (more properly, the Wilderness of the Beastlands, formerly the Happy Hunting Grounds in early versions of the game) is a neutral (chaotic) good-aligned plane of existence. It is one of a number of alignment-based Outer Planes that form part of the standard Dungeons & Dragons (D&D) cosmology, used in the Greyhawk and Planescape campaign settings, as well as some editions of the Forgotten Realms setting.
The plane known as the Happy Hunting Grounds was mentioned for the first time by name in the article "Planes: The Concepts of Spatial, Temporal and Physical Relationships in D&D", in The Dragon #8, released July 1977. The plane was mentioned again in an appendix of the known planes of existence in the original (1st edition) AD&D Players Handbook, published in June 1978, where it was described as "The Happy Hunting Grounds of neutral good chaotics".
The Beastlands is a plane of nature and animals, and is also known as the Happy Hunting Grounds. Peaceful alpine forests and groves of giant mushrooms can be found here. A varied climate exists across the plane, providing a suitable environment for many species of animals and plants. The number of traditional settlements is very small, with most inhabitants living beneath the trees out in the wilderness.
In a critical review of Planes of Conflict for British RPG magazine Arcane, Trenton Webb described the Beastlands as "a bright, simple plane that stirs the beast in players' hearts. Here the moral ambiguities of the civilised world are replaced by the simplistically honest urges to eat, sleep and mate."
The mortal souls that come to this plane after death take on animal traits soon after they arrive, developing pelts of fur and growing horns or pointed ears or other such features. Over the course of centuries they continue to slowly change, becoming celestial beasts.