Earthquake

Range: Special (500 feet)

You create a seismic disturbance in the spell’s area. Until the spell ends, an intense tremor rips through the ground and shakes anything in contact with it.

The ground in the spell’s area becomes difficult terrain as it warps and cracks. 

When you cast this spell and at the end of each turn you spend concentrating on it, each creature in contact with the ground in the spell’s area must make a Dexterity saving throw or be knocked prone .

Additionally, any creature that is concentrating on a spell while in contact with the ground in the spell’s area must make a Constitution saving throw or lose concentration. 

At the Narrator’s discretion, this spell may have additional effects depending on the terrain in the area.

Fissures: Fissures open within the spell’s area at the start of your next turn after you cast the spell. A total of 1d6 such fissures open in locations you choose. Each is 1d10 × 10 feet deep, 10 feet wide, and extends from one edge of the spell’s area to the opposite side. A creature standing on a spot where a fissure opens makes a Dexterity saving throw or falls in. On a successful save, a creature moves with the fissure’s edge as it opens.
A structure automatically collapses if a fissure opens beneath it (see below).

Structures: A structure in contact with the ground in the spell’s area takes 50 bludgeoning damage when you cast the spell and again at the start of each of your turns while the spell is active. A structure reduced to 0 hit points this way collapses.

Creatures within half the distance of a collapsing structure’s height make a Dexterity saving throw or take 5d6 bludgeoning damage, are knocked prone, and are buried in the rubble, requiring a DC 20 Acrobatics or Athletics check as an action to escape. A creature inside (instead of near) a collapsing structure has disadvantage on its saving throw. The Narrator can adjust the DC higher or lower depending on the composition of the rubble. On a successful save, the creature takes half as much damage and doesn’t fall prone or become buried.