Scholar

A Scholar is a master duelist, combat analyst, and uses their knowledge of the enemy to their advantage. They don't often support physical ability, but manage to make up and potentially be even stronger than many other combatants by utilizing their knowledge and practice for combat.

Prodigious Fighter

Beginning when you choose this archetype at 3rd level, whenever you wield a Finesse weapon, you also have the option of using your Intelligence modifier, as well as your Dexterity or Strength modifiers.

Combat Analyzer

Starting at 3rd level, your study of combat techniques allows you to learn your enemy the more you fight them. While in combat, a Scholar can use a bonus action to make a Wisdom (Insight) or Intelligence roll with a DC equal to the target creatures AC to apply a +1 to all attack rolls made by the Scholar against them. You can only have this bonus on one enemy at a time, and you can only have one +1 to attack rolls at level 3. This feature upgrades at level 7, 10, 15 and 18.

At Higher Levels: Whenever a scholar reaches level 7, 10, 15 or 18, this features upgrades. Whenever a scholar reaches one of the listed upgrades, the given DC decreases by 1, and the amount of allowed bonuses increases by 1. This means at 10th level, there would be a -2 to DC's and you can get a total of +3 to attack rolls using this ability.

Field Research

Starting at 7th level,  twice in-between short or long rests you can use an action to find an enemies damage weakness, if they have one. If an enemy does not have a damage weakness, you can roll an Intelligence check with a DC equal to 10 + the enemies CR. If it succeeds, it expends a usage of the feature and applies a random damage weakness, which you know. If it fails, you do not expend a usage. You can only apply one weakness per enemy.

Duelist

At 10th level, if you don't already have the Dueling fighting style, you gain it. Otherwise, if you have it, your additional damage upgrades to a +5 from its previous +2.

Practiced Stance

Starting at 15th level, when you end your turn in the same place you began it, you gain a +2 to AC and can make an attack of opportunity when an enemy enters your attack range until you either move out of the space or are forced to move out of it.

Desperate Action

At 18th level, you can cling on to life during combat for a short period, when most would fall unconscious. If an attack drops you to 0 hit points, you take a turn after the end of the current one. During this turn, you can not take any action to actively heal yourself, either through healing spells, potions, etc. Any damage taken acts as if you were unconscious, e.g. taking failed death saves. If you sustain 3 failed death saves during your extra turn, you die. Afterwards, if you live, you fall unconscious. You can only use this ability once per long rest.