Way of the Adamant Fist

One of the oldest monastic traditions known, monks of the way of the adamant fist - also referred to as the adamantine way by the practitioners themselves - focus on the deep and unyielding truths that the ages have carved into stone. They take a great interest in mineralogy, especially metallurgy and crystallography, being widely regarded as skillful masons, stone carvers, and sculptors, but also as famous glaziers, ceramists, and bell founders.

Novice disciples develop signature attacks like elbow blows or heel kicks due to the extensive practice required by this tradition. In return, they are rewarded with adamant resilience, raw power, and the ability to sense even the finest vibrations.

Lithic Body

When you choose this archetype at 3rd level, your hit point maximum increases by 3, and it increases by 1 whenever you gain a level in this class.

Additionally, while you are benefitting from Unarmored Defense, you can briefly condense your skin to repel blows. Using your reaction when you are hit by an attack, you can add your proficiency bonus to your Armor Class until the start of your next turn, including against the triggering attack. You can use this feature a number of times equal to your Wisdom modifier (minimum of once). You regain all expended uses when you finish a short or long rest.

Starting at 17th level, any critical hit against you becomes a normal hit while you aren't incapacitated.

Grip of the Mountain

Starting at 3rd level, when you attempt to grapple a creature using the Attack action, you can make one unarmed strike as a bonus action.

Additionally, you can channel ki into your arms and hands to tighten your grasp. At any time on your turn, you can spend 1 ki point to gain advantage on Strength checks that you make to grapple creatures or break objects. This benefit lasts until the start of your next turn.

Obsidian Soul

Beginning at 6th level, your inner self can reflect harmful magic like mirroring glass. 

When you make an Intelligence, Wisdom, or Charisma saving throw against a spell or other magical effect, you can spend 2 ki points to gain advantage on the roll. On a successful save, you can reflect the effect, provided it targeted you directly and was created by another creature on the same turn. That creature is then subjected to the effect as if it had targeted itself, unless it isn’t a valid target. If the effect requires concentration, you can concentrate to maintain it (up to its maximum duration).

Telling Stone

At 11th level, you awaken to the sacred chime of stones, entering into a nonlingual dialogue. You can no longer become lost in rocky terrain or stone environments (such as mountains, caves, or sewers), and you gain tremorsense out to a range of 30 feet. To benefit from this special sense, the ground or substance in question must be made of dirt, stone, or solid rock.

Lithic Body Improvement

Starting at 17th level, any critical hit against you becomes a normal hit while you aren't incapacitated.

Adamantine Strikes

Starting at 17th level, when you score a critical hit with an unarmed strike against another creature, your ability modifier is doubled for the attack’s damage roll.

Additionally, your unarmed strikes deal double damage to objects and structures.