At 3rd level, a fighter gains the Martial Archetype feature. The following option is available to a fighter, in addition to the options offered in the Players Handbook.

Banneret

Bannerets are fighters that are pledged to protect the crown of kingdoms, taking the fight against evil beyond their kingdom’s borders. They are tasked with wandering the land as knights errant, relying on their judgment, bravery, and fidelity to the code of chivalry to guide them in defeating evildoers. A banneret prefers to lead through deeds, not words. As a banneret spearheads an attack, the banneret’s actions can awaken reserves of courage and conviction in allies that they never suspected they had.

Crown's Command When you choose this archetype, at 3rd level, you learn various tactical orders. Command Points. You have a number of command points equal to 1 + your Intelligence modifier (a minimum of 1). When you spend a command point, you lose that point until you take a short or long rest, at which point you regain all of your expended command points. Orders. You know two orders of your choice, and learn one additional order at 7th, 10th, and 15th levels. You can only use one order per turn. Additionally, when you finish a long rest, you can replace one order you know with another one, provided you spend at least 1 hour of the rest focused on studying or learning new tactics.

Ready for Battle Also, at 3rd level, you are always prepared for battle. You have a bonus to initiative rolls equal to your Intelligence modifier (a minimum of +1).

Trusted Advisor At 7th level, you gain proficiency in Persuasion if you did not have it already, and can add your Intelligence modifier as a bonus to Persuasion checks you make. If you are already proficent in Persuasion, you gain proficiency in one of the following skills, instead: Deception, History, Insight, Intimidation.

Commander's Surge At 10th level, when you use your Action Surge, all orders you use until the start of your next turn cost no command points.

Master Tactician Beginning at 15th level, you can use any number of orders per turn, instead of only one. Also, you can take the Help action as a bonus action.

Readied Rally Starting at 18th level, when you roll initiative and have no command points remaining, you regain 1 command point.