5e School of the Disruptor

[Belac93]

This is a wizard school that is very good at fighting other magic users. Please give ideas for balance.

School of Disruption
The school of disruption is a subclass of wizard specifically focused on fighting other magic users.

Minor Counterspell
At level 2, as a reaction (or bonus action on your turn) you may attempt to use a minor version of counterspell. When you see a creature within 30 ft of you attempting to cast a spell, you may attempt to disrupt their casting. That creature makes a Intelligence saving throw against your spell save DC. If you succeed, the creatures spell fails and has no effect. You may not attempt this on a spell whose level equals more than half your wizard level (rounded down). You may use this feature a number of times per day equal to your Intelligence modifier.

Detect Arcane
At level 2, as a bonus action on your turn, you may make an Intelligence check with proficiency. For every 5 points you make on your check, you may use the spell Detect Magic, but only out to that range. You must take a short or long rest before you can use this ability again (e.g. total roll of 17, detect out to 15 ft.)

Improved Counterspell
At level 6, add the counterspell spell to your spell book. Whenever you cast this spell, you gain the following benefits.
Once per round, you may cast counterspell without using your reaction.
Whenever you succeed on countering a spell, the creature who cast the spell takes 1d6 psychic damage for each level of the spell they cast

Magic Fighter
Starting at level 10, whenever you cast a spell on a creature that can cast spells, you have advantage on your attack roll, or that creature has disadvantage on its saving throw. In addition, that creature has disadvantage on a saving throw to concentrate on any spell it is concentrating on.

Spell Resistance
Starting at level 14, you have advantage on saving throws against spells.
Furthermore, you have resistance against the damage of spells

Disrupt
1st-level abjuration
Casting Time: 1 bonus action
Range: 50 ft
Components: V
Duration: Instantaneous
Choose a creature within 50 ft of you. If that creature is concentrating on a spell, they must make a Intelligence saving throw against your spell save DC. If they fail, they lose concentration on the spell.

[Prince Zahn]

Lemme take a moment to say I always like seeing your homebrews. You're full of interesting ideas that help inspire interesting ideas in me.

1. Okay, first thing I noticed is that the Wizard's Arcane tradition always has a ribbon at level 2. (a ribbon is WotC's R&D term for fluff-based class features that make the class look better at what it does, while having some possibility of being useful, and are not considered a balancing factor in a class.) In the PHB Arcane traditions, this comes in the form of paying half price for adding spells (or a certain type of spells) into your spellbook. Try to think of something equivalent in fluff and usefullness for the school of disruption.
2. Minor counterspell and disrupt are remarkably similar. I think you are better off just choosing one.
3. If counterspell no longer requires a reaction, it quickly becomes abusable, since you're casting it for free. Maybe if you set a different limit on it it could help.
4. Magic Fighter escalates very quickly. It's an easy +5 DC against other casters. Seriously consider imposing disadvantage on the enemy caster's save instead, and perhaps adding another limitation.
5. Offering nearly universal resistance to all things magic is a bit much, Consider swapping this for something "juicier" but not as powerful. Alternatively, you might say "choose any creature within 120 feet that you can see as a bonus action, select one of the following effects:
   • You have advantage on any saving throws against spells that the target creature casts.
   • You only take half damage from any spell the target creature casts.
   
   You can change the target and/or the effect you chose, As well as activate or suppress as a bonus action."

It's just a thought or a suggestion. Apply where appropriate ^-^-b
Keep going this is pretty good!
PZ

[Ninja_Prawn]

Lemme take a moment to say I always like seeing your homebrews. You're full of interesting ideas that help inspire interesting ideas in me.

1. Okay, first thing I noticed is that the Wizard's Arcane tradition always has a ribbon at level 2. (a ribbon is WotC's R&D term for fluff-based class features that make the class look better at what it does, while having some possibility of being useful, and are not considered a balancing factor in a class.) In the PHB Arcane traditions, this comes in the form of paying half price for adding spells (or a certain type of spells) into your spellbook. Try to think of something equivalent in fluff and usefullness for the school of disruption.
2. Minor counterspell and disrupt are remarkably similar. I think you are better off just choosing one.
3. If counterspell no longer requires a reaction, it quickly becomes abusable, since you're casting it for free. Maybe if you set a different limit on it it could help.
4. Magic Fighter escalates very quickly. It's an easy +5 DC against other casters. Seriously consider imposing disadvantage on the enemy caster's save instead, and perhaps adding another limitation.
5. Offering nearly universal resistance to all things magic is a bit much, Consider swapping this for something "juicier" but not as powerful. Alternatively, you might say "choose any creature within 120 feet that you can see as a bonus action, select one of the following effects:
   • You have advantage on any saving throws against spells that the target creature casts.
   • You only take half damage from any spell the target creature casts.
   
   You can change the target and/or the effect you chose, As well as activate or suppress as a bonus action."

It's just a thought or a suggestion. Apply where appropriate ^-^-b
Keep going this is pretty good!
PZ

I agree with all of these points, except for "If counterspell no longer requires a reaction, it quickly becomes abusable, since you're casting it for free."

It's not free; it still costs a 3^rd (or higher) level spell slot. The supply of those is very limited, especially considering how many key spells are at level 3.

[Prince Zahn]

I agree with all of these points, except for "If counterspell no longer requires a reaction, it quickly becomes abusable, since you're casting it for free."

It's not free; it still costs a 3^rd (or higher) level spell slot. The supply of those is very limited, especially considering how many key spells are at level 3.

perhaps I misspoke, saying that casting a spell takes no kind of action whatsoever is abusable because of it's repercussions on action economy. While I agree that the burnout will be swift, it's far from balanced when the caster gets to add a spell each round on top of the movement+Action+Bonus Action+Reaction paradigm. Because A: messing with 5e's action economy with unrestricted means will tamper with balance, there are countless extra things you can do with the Reaction you get on top of counterspell. B: it slows down the fast pace of combat every time you cast counterspell (which is easily every round of an encounter)
For the same reason I refrain from offering an extra opportunity attack per turn (I.e. Combat Reflexes that thankfully was not converted to 5e) I disagree that casting any given spell should not have a casting time.

[Belac93]

[*]Offering nearly universal resistance to all things magic is a bit much, Consider swapping this for something "juicier" but not as powerful. Alternatively, you might say "choose any creature within 120 feet that you can see as a bonus action, select one of the following effects: [LIST][*]You have advantage on any saving throws against spells that the target creature casts.[*]You only take half damage from any spell the target creature casts.

PZ

Abjuration wizards get resistance to all magic.
The thing that I see with this is that this subclass, while powerful, is much weaker against anybody who cannot use magic. Focus vs. Versitality.
I'm changing the no reaction to: once per round, you may cast counterspell without using your reaction.
I had an idea flash while writing this, and am removing disrupt and replacing it with a sort of minor detect magic. I will add disrupt as a cantrip.