A world between the rifts
Between runs you aren't sitting in a menu. You share an overworld hub with other players, with guilds, parties, vendors and quest-givers. It is where you form a group, visit vendors and pick up quests before the next rift. Your online characters, their levels and their gear live on the game's servers, so your progress follows you from session to session.
4-player online co-op
Take any rift with up to four players. Each player brings their own hero, class and talents, so a party can split the work: one player runs the economy, another holds the main killing zone, others handle control and bosses. Mills pay wood to the whole party, and gold pickups are shared in multiplayer. The strategy guide has more on co-op roles.
Seasonal Arena: ranked PvP
The Seasonal Arena is ranked 1v1. Instead of defending against the computer, you summon monsters into your rival's rift while they do the same to you, using the gear you farmed in PvE. Climb from Bronze to Diamond before the season ends. The top players are on the leaderboards.
RPG progression that carries over
Every rift is a loot run. Characters level to 50, earning a talent point each level for the talent trees. Gear levels up, rolls new affixes and completes class sets that change your hero's abilities. The gear guide covers how it all works.
Rather play alone?
Every rift can be played solo, and you can keep fully offline characters too. The free demo on Steam includes the first eleven rifts. More answers are in the FAQ.