Planemirror
Planemirror is a term used in the context of tabletop role-playing games (TTRPGs), particularly those inspired by or based on the *Dungeons & Dragons* system. It refers to a specific type of magical illusion or mirror that creates a perfect, reflective duplicate of a plane of existence—such as the Material Plane, the Feywild, or the Shadowfrost—within its own bounded space. Unlike ordinary mirrors, which only reflect appearances, a planemirror can manifest an entire alternate version of a plane, complete with its own geography, inhabitants, and rules of physics.
The concept was first introduced in the *Dungeon Master’s Guide* for *Dungeons & Dragons* (3rd Edition) as
Planemirrors are often used in game narratives as a plot device to introduce players to unfamiliar planes
In broader fantasy literature and media, the idea of a planemirror has inspired similar concepts, such as