Rock Subclass

Earthbound Pact Your patron is Ghoroth, the Elemental Lord of Earth and Corruption. As a warlock bound to Ghoroth, you gain access to a variety of abilities that draw upon the power of the earth and the corruption that infuses it.

Expanded Spell List

The Fiend lets you choose from an expanded list of spells when you learn a warlock spell. The following spells are added to the warlock spell list for you.

Fiend Expanded Spells

Spell Level	Spells
1st	Earth Tremor, Hellish Rebuke
2nd	Maximilian's Earthen Grasp, scorching ray
3rd	Meld Into Stone, wall of sand
4th	Stone Shape, StoneSkin
5th	transmute rock, wall of stone

Earthen Might

Starting at 1st level, you can channel the power of the earth to enhance your attacks. When you hit with an attack while your target is on rock/dirt or some faccimily of the kind you can add your proficiency to the damage of the attack as the earth launches up and strikes the target in a manner specific to the enviornment ( a spike of stone, a torrent of sand, a clay spear etc). This damage is considered magical piercing or bludgeoning damage depending on DM descretion. 

Tremor Sense

Tremor Sense At 6th level, you gain tremorsense out to a range of 30 feet. You can detect the location of any creature or object that is in contact with the ground or a solid surface within that range.

Corruption's Grasp

Starting at 10th level, you can infuse your eldritch blast with the power of corruption. When you hit a creature with eldritch blast, you can choose to cause it to become diseased if so it makes a constituion saving throw equal to your spell save DC .On a failed save the creature is diseased for one minute. The creature makes a save at the end of it's turn ending the effect on a save (for every turn the target remained diseased it takes an additional 1d8 of poison damage) If the creature becomes diseased and overcomes it they cannot become diseased in this manner again in this encounter. While diseased, the creature has disadvantage on attack rolls and ability checks.

Corrupting Earth

At 14th level, as an action you can cause the ground to become corrupted in a 30-foot radius centered on yourself. The ground becomes difficult terrain for your enemies, and any creature that starts its turn within the radius takes poison damage equal to your warlock level. Additionally, any plants in the area wither and die, and the ground becomes barren and desolate for 1 year. You can use this ability once per long rest.