The Sundering refers to a significant event in the lore of the Dungeons & Dragons universe, particularly within the Forgotten Realms setting. It marks the moment when the world of Toril was split into different realms, leading to the separation of the Material Plane from the Shadowfell and Feywild. This event was caused by the actions of powerful deities and had lasting effects on the geography and magic of the world. The Sundering was initiated by the conflict among the gods, particularly involving Mystra, the goddess of magic. As a result, the flow of magic changed, affecting spellcasting and the nature of magical creatures. This event reshaped the relationships between various races and factions, leading to new alliances and conflicts in the aftermath.