A mental maze was a toy used to help train Jedi younglings in the use and manipulation of the Force. They were metal spheres of varying sizes which a person would project part of their self into. The smaller the sphere, the more complicated it would be to get out of; however, once a youngling got the hang of using the mazes, it could be easy. In 12 ABY, using Alter Mind and the maze's natural properties, Irek Ismaren tried to trap Leia Organa Solo in the smallest and most complex sphere from Plett's collection of Jedi training tools. The maze was composed of many layers of concentric spheres, linked by apertures which Organa Solo experienced as one-way gates. She also experienced frightening visions inside, though they may have originated from Ismaren or from her own subconscious.