If you haven’t played Path of Exile in a while, you might want to reinstall that client soon.

Developer Grinding Gear Games revealed that the fourth expansion for its popular PC action role-playing game comes out on March 4. Path of Exile: Ascendancy will introduce new sub-classes, items, skills, and levels.

Path of Exile is notable in the action role-playing game space, which includes the heavy-hitter Diablo III, because it’s free-to-play (with only in-game perks like extra stash room and aesthetic upgrades like special spell effects and pets costing real money). Content updates like this expansion are important for keeping Path of Exile’s 13 million players worldwide active, especially as Diablo III developer Blizzard continues to offer free updates for its game (although you still need to pay if you want to start playing Diablo III). Even with Path of Exile being free, Diablo III remains more popular. That game has sold over 30 million copies as of last August. Still, Diablo III has the might and branding of Blizzard behind it, so Path of Exile’s success is still impressive. It’s very much the David to Blizzard’s ogre-sized Goliath.

Ascendancy adds The Lord’s Labyrinth, a new area that features randomly generated areas that change every day, and Trials of Ascendancy, a new area that focuses on puzzle-based rooms. It also includes 19 Ascendancy classes, new sub-classes that can earn you new skills.

Path of Exile originally came out in 2013.