You can attack four times, instead of once, whenever you take the Attack action on your turn.

You can catch your breath in the midst of battle. As a bonus action, regain 1d10 + fighter level hit points once per short or long rest.

A fighting style is your specialized approach to combat. Choose one style appropriate to a master combatant, such as Defense, Dueling, Great Weapon Fighting, Protection, or another legal fighter style.

You can push yourself beyond your normal limits. Once per short or long rest, take one additional action on your turn.

You choose a martial archetype, which defines your signature combat techniques.

Your weapon attacks score a critical hit on a roll of 19 or 20.

You can add half your proficiency bonus, rounded down, to any Strength, Dexterity, or Constitution check you make that does not already include your proficiency bonus. You also gain proficiency in one type of skill of your choice from the fighter list if you do not already have it.

You can choose a second fighting style from the fighter list.

Your weapon attacks score a critical hit on a roll of 18, 19, or 20.

Whenever you roll initiative and have no uses of Action Surge left, you regain one use.

You are survivable enough to continue fighting. At the start of your turn, if you have fewer than half your hit points but more than 0, you regain hit points equal to 5 + your Constitution modifier, provided you are not incapacitated.

You have an excellent memory for maps and geography, and can always find food and fresh water for yourself and up to five others, provided the land offers any. In a modern setting, this becomes an uncanny instinct for routes, exits, and survival logistics in unfamiliar terrain.