From the publisher's website:

Tyrants of the Underdark pits 2 to 4 players against each other to take over territory in the tumultuous Underdark, mashing up deck-building mechanics with board control. Designed by Peter Lee, Rodney Thompson, and Andrew Veen, and produced by Gale Force Nine, Tyrants of the Underdark is a competitive board game in which you play as a drow house recruiting monsters, cultists and demons to aid you in controlling locations such as Menzoberranzan and Blingdenstone. Using power and influence as resources, Tyrants of the Underdark features multiple strategies you can use in crafting your deck of minions. Be the spymaster infiltrating your enemy's strongholds or the deadly war-leader concentrating on assassinating enemy troops. No matter how you decide to play, whoever controls most of the Underdark at the end of the game wins, unless there's some hidden strategy in play.