Martial Levels

Classes are divided into three tiers: full-martial, half-martial, and non-martial.
-Full-Martial Classes include: Barbarian, Fighter, Monk and Rogue.
-Half-Martial Classes include: Paladin and Ranger.
-Non-Martial Classes include: Artificer, Bard, Cleric, Druid, Sorcerer, Talent, Tamer, Warlock and Wizard.
If you have a subclass feature or eldritch invocation that gives you the ability to attack more than once when you take the Attack action (such as the Extra Attack feature), you are considered a half-martial character for the purposes of advanced weapon mastery, even if you belong to a non-martial class.
You become a half-martial class in this way when you select the subclass or invocation that grants this feature.

Multiclassing with Martial Levels
Your martial level dictates the levels at which you unlock advanced weapon mastery advanced techniques. You determine your martial level by adding together all your levels in the full-martial classes and half your levels in half-martial classes (rounded down)

Advanced Techniques
Advanced techniques are special manoeuvres associated with a weapon property. A character can perform a technique with any weapon that possesses that property, provided the character is proficient with that weapon, has learned the technique, and meets its prerequisites.

Saving Throws
Whenever you use an advanced technique that forces a target to make a saving throw, it is against your martial save DC, which is calculated using any modifiers to your attack rolls with the weapon you are using to perform the technique. This includes your proficiency bonus, your ability modifier, attack roll bonuses if the weapon is magical, or other effects currently affecting you or the weapon. It does not include any bonuses that rely on die rolls, such as the effect of the bless spell or Bardic Inspiration.
Martial Save DC: 8 + your proficiency bonus + your ability modifier + other attack roll bonuses

Learning Advanced Techniques

When you reach martial level 2, you learn one tier 1 advanced technique. As you increase in martial level, you learn more techniques, including more powerful ones at higher tiers, as shown in the Advanced Weapon Mastery Progression table.

Technique Trees
Advanced techniques are split into twelve technique trees, each of which is associated with one property: Ammunition, Finesse, Heavy, Impact, Light, Loading & Reload, Pugilist, Reach, Scourge, Shield, Thrown, and Versatile. Each technique tree has four tiers; to pick an advanced technique from tier 2 or higher, you must know at least one advanced technique from a lower tier in that property’s technique tree.
In addition, advanced techniques have martial level prerequisites as shown on each technique tree and in the Advanced Weapon Mastery Progression table.

Superior Strikes

Every weapon can perform a devastating attack called a superior strike. The tier 2 advanced superior strike technique of each technique tree gives you access to the superior strike for all weapons with that property.
Each weapon has a certain superior strike tied to it.

Shields
Shields are a unique case. Technically, they are classified as armour, but as any shield-bearing warrior will tell you, they can be as much a weapon as any sword or axe. Accordingly, shields have a dedicated technique tree and their own superior strike.

Performing Superior Strikes
When you take the Attack action on your turn, you can choose to make one superior strike in place of one of your regular attacks. You can perform superior strikes in this way a number of times equal to your proficiency bonus, but no more than once per turn, and you regain all expended uses when you finish a long rest. Like other advanced techniques, when your superior strike forces a creature to make a saving throw, it is against your martial save DC.
Each weapon type has a specific superior strike it can be used to perform, which is listed and described with the weapon itself.