The Geth are a synthetic race created by the Quarians to perform manual labour. The Quarians began a genocide of Geth when their true intelligence was revealed, but were defeated. The Geth now inhabit the original Quarian homeworld of Rannoch. The geth are controlled by a sort of hive mind with little focus on individuality. In Mass Effect 3, they can be wiped out, wipe out the Quarians, or live in harmony with the Quarians. Legion is a notable Geth unit.