Some monks perfect their bodies to become immovable, indestructible objects, standing as a mountain and striking like a freight train. Such monks value strength over speed and agility, relying on their ability to shrug off blows and strike through an opponent rather than at them. By honing their bodies into avatars of strength, they learn to stand their ground against mighty foes and strike with blows that can break through the strongest armor.

Iron Mountain Technique

Starting when you choose this tradition at 3rd level, you learn the disciplines that fortify your body and focus your strength.

This makes the following alteration to the basic Monk features: Monk weapons are now defined as simple melee weapons that do not possess the light or finesse properties and martial melee weapons that deal bludgeoning damage. While wearing no armor and not wielding a shield, your AC equals 10 + your STR modifier + your WIS modifier. When you attempt to deflect or catch a missile, you can substitute your STR modifier for your DEX modifier in the calculation. When you gain the Evasion feature at 7th level, you may make a STR saving throw instead of your DEX saving throw.

When you spend any of your ki points, you may voluntarily reduce your own speed to increase your armor class. You gain +1 AC for every 10 feet of speed sacrificed. This effect lasts until you voluntarily move more than 5 ft as part of your movement. You can also choose to end this effect at any time, no action required.

The Boulder Grinds

At 6th level, you gain the Crusher feat. Also, your unarmed and melee weapon attacks count as magical for the purpose of overcoming resistance and immunity to nonmagical attacks and damage.

When using your Iron Mountain technique, you now gain +1 AC for each 5 ft of movement you sacrifice.

The Spear Impales

Starting at 11th level, when you spend ki on your turn, the next unarmed melee attack you make that successfully hits a single opponent becomes a crit. You may use this ability as many times as your proficiency bonus. This ability expires if not used before you complete a long rest, and its uses refresh when you complete a long rest.

The Avalanche Begins Slowly

When using your Iron Mountain technique, if you sacrifice all of your speed, not only does your AC increase, but you become immune to all damage. For each of your turns that passes without moving, your limit that causes this effect to fade increases by 5 feet. (For example, when activated, this remains active provided you voluntarily move no more than 5 feet. After spending one turn spending 0 movement, this will remain active provided you voluntarily move no more than 10 feet. After two turns spending 0 movement, this will remain active provided you voluntarily move no more than 15 feet.) This exception cannot increase beyond your normal speed.

While using this feature to gain immunity to all damage, you also gain advantage on all saving throws against spells and effects that would not normally cause damage.