The Palace is a location in Persona 5.
The protagonist and Ryuji Sakamoto visit Shujin High School during the night time and see that the school has somehow been replaced with the Palace. Morgana describes the Palace as a world created from warped desires. In actuality, Palace is created by the distorted minds of adults.
It serves as the main battleground for the Phantom Thieves of Hearts, as the main dungeons each represent one of the Seven Deadly Sins. The exact nature of the Palace, beyond it being a world made from distorted desires of humans, is unknown, other than that it is quite massive, evident by the Mementos, a Palace that represents the entirety of humans. Each Palace also holds a Treasure, the main center of the Palace creator's warped innermost desires. Once that Treasure has been obtained, the creator of the Palace will feel deep regret for their actions, and confess to their sins. Each Palace is also inhabited by the Shadow Self of its creator, who summons demons (transformed into forms resembling lesser Shadows) to protect the Palace and to ensure the original never changes, which would weaken the Shadow (barring Shadow Futaba, who tries to use her Palace to lessen her original's depression-the boss of the Futaba Palace is actually Wakaba Isshiki's Cognitive existence, born from the belief that she hates Futaba). They are also home to Cognitive existences, living beings born of the perceptions the Palace's creators have of people in their life.
However, during the events of the story, it is revealed that, if a Palace's Shadow resident is destroyed, that person's mental state will deteriorate in the real world and they will eventually die. This is key to the plan of Goro Akechi, who uses the Palaces and Mementos as a way to safely assassinate his targets.
- The Palace is somewhat similar to the TV World of Persona 4, as each dungeon typically reflects the mentality of the one who created. Examples would include Kamoshida, who views himself as the 'king of the school,' and is reflected by his Palace, which appears to be an old castle, and Yukiko Amagi, who's dungeon was a castle that represented her feelings of being locked away by her own birth.