How do I make a campaign where PC's are in a highschool learning how to fight monsters

They're monster-hunters as a profession.

IE: Anima's Inquisitors, Witchers, MH guys, warham inquisitors, etc...

You watch too many stupid anime

>fantasy

>mfw that one player who chooses barbarian and ends up not accomplishing anything because they're neither literate nor are there classes teaching one how to be "barbaric"

DUNGEONBALL

CONTESTANTS MUST CARRY THEIR BALL TO THE ENEMY GOAL THROUGH A RANDOMLY GENERATED DUNGEON, FULL OF TRAPS, MONSTERS AND THE ENEMY TEAM. YOU GET THE BALL TO THE OPPONENTS SIDE OF THE DUNGEON AND YOU WIN. THERE ARE NO RULES.

DUNGEONBALL

SIGN UP WITH YOUR PE BARBARIAN TODAY

I actually wrote a fun thing how to pretty much rules legally climb big monsters in GURPS.

tl;dr big monsters might not care about you climbing on them (because they will certainly win the strength check if they do care).

When you are climbing on someone way stronger than you, you are basically just extra weight to them.

You can still use the MA rules for shifting your grip though (going from grabbing their torso to grabbing their arm). This lets you move around.

Hanging on to their back have significant benefits since they can only attack you with wild swings while you can keep stabbing them.

In a one against many scenario, forcing the big beastie to waste actions shaking off hangers on makes room for your teammates to attack without fear of retaliation.

You can design custom equipment as the GM to give players a fighting chance against the "shake off" roll. I also think its reasonable that the players could learn about the monsters habits to know how they deal with shakers.

tl;dr tl;dr As for your campaign: remember monsters are NPC:s too. They have a thought pattern dominated by instincts, that makes them predictable. This means you can learn beforehand how a monster will react to different threats.

tl;dr tl;dr tl;dr Read Dungeon meshi

Generic fantasy monsters, right? So, at the very worst a very powerful dragon or lich, I assume.
Weapon and magic training, first and foremost.
Anatomy lessons. Lower levels study orc, human, elf anatomy and so on. Higher levels study progressively more lethal things. Also useful when they need to patch someone up.
Smithing. Making their own weapons and armour, enhancing them with magic, and most importantly repairing them could be helpful.
Sparring against each other to test their skills.
For higher levels, strolling through bandit camps for practice.

I'd do it modern day in a world where monsters are just bullshit people need to deal with

There IS a system for that.

I once read through 100ish pages of rules in a pdf share thread about a system (dont recall the name unfortunately) that explicitly revolved about the arkwardness of a bunch of teenagers in highschool with some weird (noire I believe) monsters and SAN stats and whatnot

It felt very twilight - or at least how I think that POS book would feel, judging by the rumors one hears about it.
Was very edgy too - it had a "Strings" stat that would measure how much some characters could influence/bully/convince/... others to do stuff, and then when someone had too many on you (or you on them, or something else) you would "trip" and change to your character classes' "darker self" (werewolf, ghoul, etc - like I said, very edgy) until something else happened...

then I noticed I just spent ~2 hours to understand Twilight - the RPG and felt not very good about myself

Pull a Dino Crisis.

Town gets sucked into the past (or future for A TWEEEST) and has to deal with everything that involves.

It's called MonsterHearts. And it's less for what OP's talking about and more for doing supernatural high-school drama, my usual example is Buffy. It's actually a pretty well designed system. I'm running a campaign of it currently with little to no angst and it's quite fun.

>MonsterHearts
>supernatural high-school drama
that about sums it up.

Dude, barbarian track is probably fucking epic. "What's your finals week looking like?" "Oh, me and the other barbs are going to go trek through 150 miles of wilderness with nothing but slings and axes while Professor Murg gives us some pointers on being able to rage enough to walk into an arrow while still maintaining enough control to function in town. Truth told I'm kinda looking forward to it."

That one's MonsterHearts, which is awesome in a sort of American Horror Story meets Buffy the Vampire Slayer sort of way. Downside is that it's very, very interpersonal drama focused. One of my favorite systems but probably not what OP is looking for.

My suggestion is John Wick's "Eldritch High," which is a bit more Harry Potter and the Vampire Academy. It plays with decks of standard playing cards instead of dice and uses some narrativist resolution mechanics based on the party having pretty dramatic imbalances in power levels, but that's actually a lot of the fun.

Available direct from the author at johnwickpresents.com/product/eldritch-high/ but you might find it cheaper elsewhere if you catch my drift which I think you do.

Ever play Mana Khemia?

>How do I make a campaign where PC's are in a highschool learning how to fight monsters
pretty sure that's not something that one would learn at high school (grammar school if we are talking medieval times) You gotta go to a trade school to learn proper monster hunting theory and techniques.

would "monster hunting" be B.A. or B.Sc.?

Take a page from Rowling's book an have investigations take up their term time.

Shamelessly rip off RWBY, anime clichés and all.

And yet they somehow still end up passing, for all their faffing about on non-school stuff

That's a good scenario for introducing players to a new system.

That sounds awesome actually

Start the game where they've already graduated. Slice of life is shit.

Masters degree equivalent

Any Witcher fans? A game set in Kaer Morhen a few centuries before it fell would be awesome

This