Pech are diminutive fey originally from the Plane of Earth. They were used as a slave race by the enigmatic Vault Keepers, tasked with constructing and maintaining the enormous Vaults of Orv. After the departure of their masters, the pech have adapted and created tiny societies hidden away in the Vaults. Some pech fled upwards to Nar-Voth where they mutated into the first derro.