On Specialists

I love wizards. It used to be that when I made a character for a Dungeons & Dragons game, I waited to see what everyone else was playing first, and picked a class which met some unfulfilled role in the party. Because, until recently, there was only one Intelligence-based class in 5th edition, this usually meant I'd be playing a wizard.

One thing I've never liked about 5e wizards (and a lot of 5e's spellcasters in general) is how same-y they all feel. Gone are the days when the Dungeon Master picked which spells the wizard had in their spellbook. Players now have total freedom over their spell selection. The scope of the game has narrowed at many tables to be primarily about combat - some might argue it's always been that way, but early dungeon-centric campaigns like Castle Greyhawk seem to have been at least equally about exploration. There is a proliferation of content on YouTube which concerns itself primarily with ranking the "best" spells, which means experienced players who want to optimize their characters tend to pick the same "must-have" spells every time - mage armor, magic missile, shield, misty step, counterspell, fireball, etc. 

(As an aside, this is why I like playing with new players, and try not to steer them towards the "good" spells unless they ask for my advice - they haven't yet closed themselves off to the possibilities of less "optimal" spells, and it's often a delight to watch them find ways to use those spells.)

Certain subclass abilities incentivize picking spells from an Arcane Tradition's school (Arcane Ward is recharged by casting abjurations, diviners can regain spell slots from casting certain divinations, Sculpt Spells only works with evocations, etc.), but even the Savant feature that each specialist gets only incentivizes learning spells from one's specialized school of magic outside of the leveling system (the feature reduces the gold cost of scribing spells, so a specialist wizard is better off learning other spells on level up and then getting the ones they want from their specialized school by other means).

All wizards tend to have the same spells, aside from those oddballs picked up from spell scrolls in treasure hoards and from enemy wizards' spellbooks. An abjurer's Arcane Ward might make them play slightly differently than a diviner with their Portent or an evoker with Sculpt Spells, but by and large, they're all probably going to have very similar repertoires.

Specializing Specialists

Advanced Dungeons & Dragons 2nd edition did specialist wizards differently. Specialists gained additional spells per level from their chosen school, received a bonus to saving throws against spells of their own school, imposed a saving throw penalty on their enemies when they cast spells of that school, had an improved chance to learn spells of their school, and could more easily create new spells within their school. The trade-off was that each school had a school of opposition, from which the specialist was forbidden to learn spells.

Later editions did away with this aspect of specialists along with most other restrictions on player character choice, and wizards became meta-chasing casters like everyone else, casting whatever spells D&D YouTubers told them were most optimal, albeit with a few bells and whistles of varying usefulness.

In my 5e games, I offer a house rule for wizards who choose the abjuration, conjuration, divination, enchantment, evocation, illusion, necromancy, or transmutation Arcane Traditions:

Starting at 2nd level, whenever you gain a wizard level, you can add one wizard spell to your spellbook, in addition to the two you already learn (as described in Spellcasting). This additional spell must be of the school associated with your Arcane Tradition. Additionally, when you make a saving throw against a spell of the school associated with your Arcane Tradition, you have proficiency on that saving throw attempt, even if you normally lack proficiency. When you cast a spell of the school associated with your Arcane Tradition which forces a saving throw to resist its effects, you can give one target of the spell disadvantage on its first saving throw made against the spell.

Additionally, you have advantage on Intelligence (Arcana) checks to learn spells from your Arcane Tradition’s school from spell scrolls.

It's a small bonus, but I think that it, along with the subclass features already included in each Arcane Tradition, gently nudges wizard players towards leaning into their specialization, if they have one.

Side Note: I also imported a spell research downtime activity based on 2e's system, which benefits specialists who choose to create new spells within their school of magic, but that is probably beyond the scope of this post.

Schools of Opposition

Another way to..."encourage" a player to lean into their wizard archetype is to reintroduce schools of opposition - that is, schools of magic from which a specialist cannot learn any spells. This is not something that fits nicely with new school playstyles, and more experienced players who are familiar with "must-pick" spells and the "meta" of wizards may chafe at the restriction. It may be worthwhile to offer the aforementioned house rule as an optional bonus if the player opts-in to locking themselves out of opposition schools. If that isn't to their liking, the DM can just leave specialist wizards as they are.

The schools of opposition are as follows:

• Abjuration: Illusion and Transmutation
• Conjuration: Divination and Evocation
• Divination: Conjuration
• Enchantment: Evocation and Necromancy
• Evocation: Conjuration and Enchantment
• Illusion: Abjuration, Evocation, and Necromancy
• Necromancy: Enchantment and Illusion
• Transmutation: Abjuration and Necromancy

I'll admit there's not much rhyme or reason to this aside from being how it was done in 2e, but one can derive some meaning from it: Wizards schooled in the more subtle arts of enchantment and illusion don't have the skill or inclination to invest time and gold into learning crude battle magic like abjuration and evocation, or the dark arts of necromancy - why reanimate a corpse when you can trick the living into doing what you want? Inversely, necromancers are much too isolated in their gross crypt laboratories to learn magic that relies on understanding people - and why would a wizard preoccupied with the undead choose to learn spells which largely don't affect them? Summoned creatures get in the way of evoker's blasting magic, and they'd rather blow someone up than charm them. Diviners know too much about the nature of the multiverse to start conjuring creatures from who-knows-where. Conjurers use refined, artisanal magic to create more sophisticated effects than the instantaneous blasts of evocation, and they have no need for divination, as they can simply acquire information from the extraplanar creatures they summon, or traverse the planes and find knowledge for themselves.

When one looks at the schools of magic and which spells belong to which school, it becomes apparent how blurry the lines are - why is necromancy, the magic of life and death, not responsible for curative magic? Why is fear, a spell which triggers an emotional state in its targets, an illusion and not an enchantment? 

I think of this as a feature of D&D's magic system, not a bug. The schools are not indicative of what kind of magic is possible within each school, but rather the approach used to achieve the magic's effects. Necromancy is not responsible for healing magic because it primarily deals in "dark" magic. Fear is an illusion because it works like that scene in Fellowship of the Ring where Gandalf makes himself appear very big in order to scare Bilbo back to his senses ("I am not trying to rob you! I'm trying to help you.").

When one thinks of magic this way, its various schools become almost like monastic traditions - wizards are disciplined in a certain approach to magic, and stand in opposition to incompatible disciplines. An illusionist might see a necromancer as an affront to magic itself. The two might engage in battle whenever they meet, and their approaches would look very different - the illusionist may use their magic to confuse and misdirect the necromancer's simple-minded minions, then shatter the rival wizard's mind with powerful fear effects, or the necromancer might come prepared with undead specifically created to see through such magic, forcing the illusionist to resort to trickery and obfuscation to escape the enemy's minions. They're not both going to stand 120 feet apart slinging fire bolt and blocking with shield.

I don't care much for D&D YouTube - content there is often preoccupied with player character builds, ranking character options into tier lists based on their "power" in a featureless white room combat, or trying to be "funny" ("This is what it would be like if Skyrim players played D&D!"). One of the only channels I really enjoy is WebDM, and they have a great series on the schools of magic in D&D, which is a good place to start thinking about these things.

Other Specialists

It isn't just wizards who need to work within the confines of their discipline in 2e. Priests' spells were broken into spheres, with each deity granting and barring access to specific spheres, while druids were simply priests of natural spirits and old gods, with access to spheres that suited their style of worship.

There's a world in which every Divine Domain, Druid Circle, Sorcerous Origin, Otherworldly Patron, and maybe even Sacred Oath and Ranger Conclave has its own, totally unique spell list. I like Domain, Circle, and Oath spells because they offer a happy middle ground, wherein spellcasters automatically have convenient access to the spells that fit their theme, but can still prepare the "optimal" spells they might prefer (although this usually means that the subclass-specific spells don't see much use unless they're particularly "good").

Even then, this method isn't applied consistently. Otherworldly Patron spells are added to the warlock spell list, but the warlock still has to choose them as known spells (foregoing potentially "better" vanilla warlock spells), and some rangers and sorcerers get bonus spells, but not all.

One solution to this is to give all Ranger Conclaves and Sorcerous Origins bonus spell lists (which I've done in my games). An option for warlocks would be to give them their Otherworldly Patron spells for free (which I've done as well). But how do you encourage players to actually use these spells over the "optimal" ones?

Like with wizards, some subclasses have moved towards solving this problem by granting certain benefits when casting subclass-specific spells (and others that fit with the theme) - Life domain clerics heal better, Circle of the Shepherd druids have more durable summons, Storm sorcerers can cause damage to enemies near them whenever they cast a lightning or thunder spell, etc.

I encourage players to lean in to the theme of their subclass's specialization. When I play an Aberrant Mind sorcerer, I'm only taking spells which can pass for psionic effects. When I play a Divine Soul sorcerer, I'm only taking cleric spells. When I play a Draconic sorcerer, I'm playing an elementalist. My Shadow sorcerers are necromancers. My Storm sorcerers only use weather magic, etc.

I find that the world feels much more rich when spellcasters of a given type use different approaches to magic and a different selection of spells. Each wizard, cleric, druid, or the like feels more unique and memorable. Ultimately, this is something players most likely have to decide they want for themselves. The DM can't force this kind of playstyle, but they can offer incentives for players who embrace it.