5e Cavalier - Fighter Subclasses

This mod officially supports the transition to the 20th level with expansion. Other similar fashions are likely to work, but I don't test them.

I strongly recommend you to use this mod 5e Action economy or other similar mod (for example, Zerd).

Kavaler

The archetypal cavalry is successful in equestrian combat. Normally born in a noble environment and brought up at court, a cavalry officer feels at home by leading a cavalry charge or exchanging speeches at a state dinner. Cavaliers also learn to protect from harm those in their care, often acting as protectors of their superiors and the weak. Forced to correct mistakes or gain prestige, many of these fighters leave their lives in comfort to embark on a glorious adventure.

Source: Xanathar-wide travel guide

Bonus Skill

When you choose this archetype at 3rd level, you gain proficiency in one of the following skills of your choice: Animal Handling, History, Insight, Performance or Persuasion. Alternatively, you learn a single language of your choice.

IMPLEMENTATION: Rules as written, minus the language part.

Born in the saddle

Starting at 3rd level, your rider skill becomes apparent. You have the advantage of saving throws made not to fall off your horse. If you fall off your horse and drop no more than 10 feet, you can land on your feet if you are incapacitated.

Finally, landing or dismounting a creature will cost you only 5 feet of movement, not half your speed.

IMPLEMENTATION: All this feature is useless in BG3, so instead you will receive 25% less fall damage, and on the first move of the battle your speed will increase by 30 minutes (to simulate the speed of riding a combat horse in desktop mode).

Unwavering Label

Starting at 3rd level, you can threaten your enemies by disrupting their attacks and punishing them for harming others. When you hit a creature with a melee weapon, you can tag the creature until the end of the next turn. This effect ends prematurely if you are incapacitated or die, or if someone else marks a creature.

As long as it is within 5 feet of you, the creature you mark has the advantage of any attack roll that is not your target.

Additionally, if the creature you flagged deals damage to anyone other than you, you can make a special melee weapon attack against the flagged creature as a bonus action on the next turn. You have the advantage of throwing an attack, and if it hits, the attack weapon will deal additional target damage equal to half your fighter level.

Regardless of the number of creatures you've tagged, you can use this special attack a number of times equal to your power modifier (at least once), and you will recover all usage spent on it when you've finished your long rest.

IMPLEMENTATION: Rules as written. Turn it off if for some reason you don't want to mark with your attacks. Additional attacks will be unlocked in your Quick Access Toolbar when the conditions are met.

Defense maneuver

At 7th level, you learn to deflect blows directed at you, your horse, or other creatures nearby. If you or a creature you see within 5 feet of you is hit by an attack, you can throw 1d8 as a reaction if you own a melee weapon or shield. Throw a die and add the dropped number to the target AC against this attack. If an attack does hit, the target has resistance to attack damage.

You can use this feature a number of times equal to your Constitution modifier (at least once), and you will recover all the usage spent on it when you finish your long rest.

IMPLEMENTATION: Rules as written.

Hold the defense

At 10th level, you become a master at blocking your enemies. Creatures provoke an attack of opportunity on your part when they move 5 feet or more while within your reach, and if you hit a creature with an attack of opportunity, target speed drops to 0 until end of current turn.

IMPLEMENTATION: Rules as written in some game restrictions - this will fairly reliably cause opportunity attacks for enemies moving within your reach (i.e. circling around you). This will depend on the reach of your weapons and the abilities that extend the range of my subclass, "The Way of the Giant Barbarian" (if you want a multi-class). It does not scale with beetles from the Fantastic Multiverse (Long Limbed does not apply to RAW attacks).

Ferocious horse

Starting at 15th level, you can catch up with your enemies, whether you are riding or not. If you move at least 10 feet in a straight line just before the creature attacks and hit it with an attack, that target must successfully make a Force save (DC 8 + your skill bonus + your Strength modifier) or it will be knocked down. You can only use this feature once on each of your moves.

IMPLEMENTATION: The rules as written with the concessions in mind. Rush spells in the game are the only way to ensure you move in a straight line (and they look cool), so you gain a charge ability that will move you as far as you want by the distance you have moved in a straight line. At the end of this movement, your next attack (ranged attacks and spells also count toward RAW) is likely to knock the target off its feet. If you move again or take any action other than an attack after charging, you will lose the ability to knock the target down.

Vigilant Defender

From level 18 onwards, you respond to danger with extraordinary vigilance. In combat, you get a special reaction that can be used once on every move of a creature other than yours. You can only use this special reaction to make an attack if possible, and you cannot use it on the same turn on which you use your normal reaction.

IMPLEMENTATION: Rules as written. This will be adjusted based on your reach (see Hold the Line) and whether you have the Armor Skill.