Add your rank of in this skill to your defensive rolls with a shield.
Shield Attack: As a bonus action you can make an attack with your shield, for which you add your STR and Shield rank to attack rolls. On hit with this attack you will push your target 1d6 x 5 feet, and it will fall prone if it has less strength than you. You must move at least 5 feet to make a shield attack and when you make a charge you will inflict 1d6 bludgeoning damage, which is modified by your strength as if it were a physical attack.
Protect allies: You can defend an adjacent ally as a reaction, using your shield to protect them. If you do so, you will use your roll instead of the ally’s defense roll. If the attack hits you will be damaged instead of your ally.
Intercept: You can spend a move action to prepare yourself to intercept an enemy attack at any time during the round. When using this ability you can charge at a moving enemy and make an attack of opportunity with your shield at any point in the round. If you manage to hit, your target must immediately stop moving. Using Intercept will immediately bring you out of your Defensive Form and you will lose prepared actions if you take damage or dodge.
Defensive Form: You have the ability to enter a state of absolute defense, becoming an impassable barrier. Entering defensive form costs a move action and while you remain in this state increase your STR and CON by 1, and your Shield defense roll by 2. You will also receive resistance equal to your rank against combat maneuvers. Defensive Form can only be used for a number of rounds equal to your rank + 1 and ends when you move or are fatigued. This ability can only be used if you are carrying a shield.
Powerful Charge: Whenever you hit a target after charge once per round you can force your target to roll CON against your attack roll, stunning him in case he fails. Increase the base damage you inflict after a charge by 2 and whenever you charge you will cause creatures with less strength than you to instinctively move out of your way, leaving you free to attack. At rank V you will increase the charge damage additionally by 2.
Moving Barrier: When you enter defensive form you grant cover to all creatures behind you in a 15-foot cone, granting them advantage in all defensive rolls. You gain the ability to move while in defensive form, but to do so you must spend a standard action or take 2 non-lethal damage.
Guardian: You gain immunity to flanking and surprise attacks whenever you enter defensive form. In addition, entering defensive form increases your DEF by 2 and enemies adjacent to you will have disadvantage attacking your allies.
Hold position: Once per round you can make an attack of opportunity against a creature that passes through the area of your reach. The attack must be made with your shield and on hit the target must be stop moving immediately. This ability can only be used if you are in defensive form.
Shield Mastery: Entering defensive form grants you an additional +2 bonus on shield rolls and increases all stat boosts by 1. You grant additional superior cover to allies you protect with a mobile barrier and may move 5 feet in reaction to protect an ally.
Parry spells: The shield can protect allies from magical attacks. On a successful defensive roll with your shield to block an area magic attack you can cancel the attack immediately, preventing all your allies behind your defensive barrier from taking obligatory area damage. You will also not suffer damage from area attacks if you successfully defend yourself with your shield.
A base shield is made of wood and allows grants you a +4 bonus in defense rolls but it will reduce your DEX by 1. Whenever an attacker hits a shield with a critical hit or you roll a critical miss the shield’s defensive bonus will be reduced by 1. A shield can be modified with the following traits to create all types of shields: