Reach Weapon Mastery

Private Pontefract held back the horde with only three weapons: a pike, a narrow hallway, and determination.

Reach Property.
This weapon adds 5 feet to your reach when you attack with it, as well as when determining your reach for opportunity attacks with it.

Weapons With The Ammunition Property:
-Glaive, Halberd, Lance, Pike.

Tier 1 Advanced Techniques.

Fortified Position

Prerequisites: martial level 2, proficiency with at least one Reach weapon
While you are wielding a Reach weapon and aren’t restrained or incapacitated, the area within 10 feet of you is difficult terrain for creatures of your choice.

Pole Vaulter

Prerequisites: martial level 2, proficiency with at least one Reach weapon
You have trained to use your weapon to aid you in vaulting and falling safely. While you are wielding a Reach weapon, if you move at least 10 feet on foot immediately before the jump, your jumping distance is tripled until the end of this turn. In addition, when you fall and are wielding a Reach weapon, you can subtract up to 50 feet from your fall when calculating falling damage. You can’t gain this benefit if you are unconscious.

Tier 2 Advanced Techniques.

Superior Strikes; Reach

Prerequisites: martial level 6, a tier 1 Reach advanced technique
You can perform a superior strike with any weapon that has the Reach property.

Tier 3 Advanced Techniques.

Constant Vigilance

Prerequisites: martial level 10, a tier 2 Reach advanced technique
When a creature enters your reach while you are wielding a Reach weapon, you can use your reaction to make an attack against that creature with the weapon.

Lunging Strike

Prerequisites: martial level 10, a tier 2 Reach advanced technique
When you take the Attack action on your turn, the reach of attacks you make with Reach weapons increases by 5 feet until the end of your turn.

Tier 4 Advanced Techniques.

Crowd Control

Prerequisites: martial level 14, a tier 3 Reach advanced technique
When you hit a creature no more than one size larger than you with a Reach weapon, you can move it up to 10 feet horizontally to an unoccupied space.

Pike Wall

Prerequisites: martial level 14, a tier 3 Reach advanced technique
While you are wielding a Reach weapon and you are within reach of an allied creature who is also wielding a Reach weapon with which it is proficient, you gain a +2 bonus to your AC. This effect does not stack.