Monks who follow the Way of The Mountain follow a discipline not seen by other monasteries. While others choose to flow like water or move like the wind, these monks remain resilient like stone, not flinching at their foes attacks, and making each deliberate movement crash down upon their enemies like an avalanche. Those who practice this way may find themselves meditating at mountain elevations where few could even catch a breath, or training underneath the crashing tide of a waterfall. To experience pain is life, to acknowledge it is a choice. All Way of The Mountain Monks follow this mantra:

Resilient as stone, unbreakable. 

Be still, but crash down as an avalanche.

Retaliate against those who try to break you.

Show them all the strength of the mountain.

- Old Mountain Proverb

 

Resilience of Stone

3rd-level Way of The Mountain feature

Those who choose this path understand that they will endure an endless barrage of attacks, so they have learned to increase their vitality in order to better weather the storm. When you choose this subclass, you increase your hit point maximum by 3 and increases by 1 again whenever you gain a level in this class.

Unbreakable Stance

3rd-lvl Way of The Mountain feature

What separates the Way of The Mountain from other monastic traditions  is their choice to brace and endure damage, rather than to gracefully dodge their foes attacks. As a bonus action, when you expend 1 ki do perform Patient Defense, you can instead enter an Unbreakable Stance, rather than taking the dodge action. Performing Patient Defense in this way allows you to become resistant to bludgeoning, piercing, and slashing damage for one minute. 

Impending Avalanche

6th-lvl Way of The Mountain feature

Monks who make it this far in their training learn to imitate the potential destruction of an avalanche, whether that be by firmly planting their feet to strike with the force of a boulder, or by crushing their enemies beneath them like were crashing down a mountain. If you did not use your movement the previous turn, all melee weapon attacks you make are at advantage, only if you do not expend any movement that turn as well.

Additionally, if did not expend any movement the previous turn, if you then move 20ft in a straight line, you can attempt to trample a target of large or smaller as an action. When you do this, the target must make a strength saving throw against your ki saving throw, taking bludgeoning damage equal to 2 rolls of your martial arts die on a failed roll, or half damage on a successful one. 

Earthen Retaliation

11th-lvl Way of The Mountain feature

Contrary to what your foes may think, your defensive posturing gives you an incredible offensive advantage, utilizing their own attack against them. When Unbreakable Stance is active, if a target of huge or smaller hits you with a melee weapon attack, as a reaction you can expend a ki point make a grapple action, adding your Dexterity modifier to the roll.

If you succeed on the grapple action, as part of the same reaction you throw the target to the ground, moving them to an unoccupied within 5ft of you and dealing bludgeoning damage equal to 4 rolls of your martial arts die. The target is also restrained on top of being grappled. The target must succeed on the grapple check to end both the grapple and being restrained. If the target you have grappled hits you again and you have access to your reaction, you may use the feature again.

Strength of The Mountain

17th-lvl Way of The Mountain feature

The discipline you have endured has led you to fully embrace the mantra that has guided your teachings. Your body has become as durable as the mountain itself, and with your mastery of ki, you can become a nearly invincible powerhouse. As a bonus action, you can expend 6 ki points to enter a special form. This form can take on many appearances, such as your skin becoming gray and rough like granite, or smooth and jet black like obsidian. When you enter this form, you gain the following benefits:

• You gain an immunity to bludgeoning, piercing, and slashing damage.
• When you use the Deflect Missiles feature, you automatically reduce the damage to 0, and can make the reaction ranged attack without expending a ki point. 
• You cannot be knocked prone and cannot be forcibly moved by any means. You automatically succeed any saving throw that would force you to move.

These benefits lasts for 1 minute.