RIFT is set in the world of Telara, a beautiful land created by the Vigil and in serious danger of being taken over and destroyed by the Blood Storm. The two major factions that have stepped forward to save Telara are the Guardians and the Defiants.
Guardians are resurrected by the gods known as the Vigil 20 years after their deaths at the hands of Regulos. The Guardians' mission is to defend Telara by devoting themselves to the the Vigil. The Guardians believe that they have been chosen by the Vigil to be Ascended because of their faith, and that by following the Vigil, only they can protect Telara.
The Defiants are resurrected at some point in the future through machines powered by souls. In the future, the Defiants see that Telara will be doomed, as it is on the verge of being completely obliterated by Regulos. The Defiants' mission is to change the course of history by traveling back in time, and they will do anything necessary to prevent the future end of the world timeline from ever occurring. Defiants have completely shunned and turned their backs on the Vigil. They refuse to sit idly by and wait for a divine miracle. The Defiants know that the only way to save Telara from the Bloodstorm is to take matters into their own hands, which they do by creating new technology and magic, fueled by sourcestone capable of creating dangerous but powerful planar powers, weapons, and defenses.
Though Defiants are resurrected by machines and Guardians by divine intervention, Telarans refer to both factions collectively as the Ascended.
Rich with history and lore, the world of Telara will reward those capable enough of triumphing over its many dangers and defeating the massive planar invasions that pour forth from the rifts. A player can walk across the face of Telara without encountering any load screens, since it is a seamless world without any 'zone lines' (except for instances, such as Chronicles, Dungeons, Slivers, and Raids. The Ascended can complete these in groups of 2, 6, 10, and 20, respectively. 
Telara is vast, and its total size is unknown, but much bigger than what players currently see on their map. Ember Isle has been rediscovered, and rumors are a new area known as the Planetouched Wilds exist somewhere near the Droughtlands. So far we know the names of the following parts of Telara:
- Bailey Hill
- Cliffside Vale
- Deepstrike Mines
- Hedgerow Court
- Ironpine Outpost
- Overwatch Keep
- Port Scion
- Quicksilver College
- Shadefallen Keep
- The Shadowlands