Root Underworld Expansion Guide: Duchy, Corvids, Mountain & Lake
Root: The Underworld Expansion adds two factions and two new maps. The Underground Duchy builds a minister-driven engine, while the Corvid Conspiracy uses hidden plots and deception.
What Underworld adds
- Underground Duchy faction
- Corvid Conspiracy faction
- Mountain map
- Lake map
- Map-specific systems including blocked paths and the ferry
Underground Duchy
The Duchy establishes buildings on the surface and sways ministers into service. Ministers expand the faction’s action capacity and scoring potential, but losing important buildings can cause political consequences.
The faction rewards building a stable infrastructure while protecting the pieces that support its minister engine.
Corvid Conspiracy
The Corvids place facedown plot tokens that may represent different effects. Opponents know a plot exists but not necessarily what it is, creating bluffing and risk-assessment decisions.
The Corvids are less about maintaining a large conventional army and more about forcing opponents to spend actions checking, removing or avoiding threats.
Mountain map
The Mountain map begins with blocked paths. Players can clear routes during the game, changing connectivity and opening new movement lines. Control around the mountain pass also creates a distinct positional objective.
Lake map
The Lake map uses a ferry to alter movement around the board. The ferry creates a shared transportation opportunity, changing which clearings are effectively adjacent for tactical planning.
Does Underworld require Root?
Yes. Leder Games lists Underworld as an expansion requiring the Root base game.
Who should add Underworld?
Underworld is a strong early expansion because it adds both faction variety and map variety. Groups that want to refresh geography as well as faction matchups get more structural change than from a faction-only box.
Related guides
Publisher sources
Expansion details checked September 2026.