Circle of Darkness

The subterranean environment can be quite unforgiving for those unfamiliar with the nature of the land. Hidden from daylight, cold and damp, makes it a unique biome that offers druids who chooses this land as their circle for it holds secrets that can only be found beneath the ground.

Naturally Adapted

You naturally adapted to the Underdark: you have a darvision of 60 ft, you ignore difficult terrain, when in the Underdark. Additionaly you gain resisatance to psychic damage.

Circle Spells

Darkstones

Starting at 3rd level, you know the cantrip Magic Stone and it doesn't count against your cantrips known. When you cast this cantrip, you can now imbue a number of additional pebbles with magic equal to your druid level divided by 3.

At 5th level, when you use your action to attack with a pebble, you can throw up to 2 pebbles at once.

Cavernous Whispers

At 6th level, your time within the underdark has developed your senses to thrive within the land beneath. You gain darkvision out to 60 feet. If you already have darkvision, this extends to 120 feet.

In addition, you gain bonus to your Wisdom (Perception) score and Passive Perception equal to your proficiency bonus while you are in darkness or half of your proficiency bonus while you are in dim light.

Sight of the Dark

At 10th level, you can momentarily heighten your senses, granting you the ability to feel the earth around you. As an action, you can spend a minute to gain tremorsense out to 30 feet until the end of your turn.

You can use this feature a number of times equal to your Wisdom modifier (minimum of once) and regain expended uses at the end of a long rest.

Descent to the Underdark

At 14th level, you can call upon the land beneath, sinking everything into the world below. As an action, you can choose any number of unoccupied spaces that you can see within 60 feet. You then sacrifice 5 feet of movement for each space and turn it into unstable ground, with your remaining movement determining the depth of each space, with a minimum of 5 feet in depth.

An unstable ground acts as a pitfall trap and when a creature moves into that space, they must succeed a Dexterity saving throw against your spell DC or fall and be knocked prone. If an unstable ground is left untouched for 1 minute, it reverts to normal.

Once you use this feature, your speed is reduced to 0 until the start of your next turn.

An example would be a druid with 30 feet of movement can choose to either create 5 unstable grounds, each being 5 feet in depth, or can create 3 unstable grounds, each being 15 feet in depth, or a single unstable ground with a depth of 25 feet.