Of the jobs given by the Fire Crystal, the Scholar is one of the more off-beat ones. Thier main selling point is their unique abilities: Scan does exactly what the name suggests and looks for enemy weaknesses. Peep, on the other hand, tells the player the enemy's current and total health. These essentially turn the scholar into a walking strategy guide, albeit one that the user has to give up a slot in the party for.
The remake makes some interesting changes to the Scholar. They're given the ability to cast magic; It's only up to level 3 but their Int increases in step with their levels meaning that a late game Scholar will have a beefy magic stat. Peep and Scan have been merged into Study which throws in the ability to remove enemy buffs for good measure. By far the most game-changing ability Scholars posses is the passive Item Lore. This passive ensures that applicable items used mid-battle have double effectiveness. Crucially, this includes attack items - meaning that weaknesses go from x2 to x4 effectiveness and Chocobo's Wrath is now Double Flare.
However, the thing that ultimately gets the scholar is their horrid Stamina. In the Famicom version, their vitality is in the single digits for most of their levels and caps at 15. While not as hilariously terrible, the remake Scholar's vitality levels are still the lowest in the game at their respective levels, capping at 38. All of this means that gaining too many levels as a scholar can cripple your characters in terms of HP which would require the player to plan around if possible. So the Scholar should be used wisely, if the player chooses to use it at all.
Scholars uniquely use books as weapons. Note that in the 3D remake, books cannot be purchased and are only found.
The Scholar's unique command and main advertised ability. In the Famicom version, it was two seperate commands: Scan for weakeness/resistences and Peep for HP. The remake merges them into a single command, making it more convenient. Despite one of its key features being invalidated if the player uses a strategy guide, it still has its uses: It also displays the current HP, giving the player an idea on how close they are to ending the fight and the remake adds a subtle cast of Dispel into the mix, making it good for when enemies use Haste or Protect on themselves
Scholar's other, infinitly more useful ability. Items used by the Scholar have their effectiveness doubled. This is only mildly useful when it comes to potions, as much as healing 1000 HP is. When it comes to offensive items, however, the Scholar hit above their weight class. Attack items in Final Fantasy III are largely elemental, based on the -ara/-aga spells, and the one non-instant kill standard item is the equivalant of Flare. Even the fearsome Garuda becomes a complete joke if a Scholar with a Raven's Yawn faces him. Even if the Scholar can't hit a weakness, that's still x2 effectiveness: Meaning that a Scholar using these items will still outpace standard magic casts of those spells.
The Pixel Remaster retains the ability, but renames it to "Alchemy" and moves it to its own dedicated command. It also highlights affected items in yellow so that the player can immediately know what items are worth using.
Due to the nature of items in FF3, Item Lore does not work outside of battle.
Thieves are a must when running a Scholar. The most reliable method of replenishing attack items is via stealing them with a Thief. Aside from that, magic users or Rangers with elemental arrows can make the most out of the weakness that the Scholar can uncover. Physically using books is an option, albeit one that would require a Knight aor some other form of defense given the Scholar's poor vitality.
For similar reasons as running a Thief, Scholars benefit greatly from the DS version's item duplication glitch: A glitch that allows the player to attain 99 of any item. Via such a glitch, it'd be an easy and reliable to stock, say, 99 Chocobo's Wraths and turn the Scholar into a nuking menace.