When I DM, I try to put a few rules and descriptions on the various schools of magic. I tend to explain this early to my players and use them for my rulings.
For example, the paladin's divine sense and ranger's primeval awareness both count as divination at my table. So they don't work on people with nondetection casted on them.
Shapechangers have advantage against transmutation spells but take double damage while transformed against their will.
I also use the "Evocation are magic. Conjurations are real (but may be real magic)" idea. So some cunjuration spells work in antimagic fields and magically dead zones if casted from outside. Dragon breath is evocation.
Then there are all the flavor aspects of the schools. Some thing necromancy is evil. Rituals can be invented base on the schools. Wild mage and lycantrope blood has hints of transmutation. Airships which run on evocation are less effecient than ones which run on conjured fuel.
So does spell school matter to anyone but wizards in your games?
For example, the paladin's divine sense and ranger's primeval awareness both count as divination at my table. So they don't work on people with nondetection casted on them.
Shapechangers have advantage against transmutation spells but take double damage while transformed against their will.
I also use the "Evocation are magic. Conjurations are real (but may be real magic)" idea. So some cunjuration spells work in antimagic fields and magically dead zones if casted from outside. Dragon breath is evocation.
Then there are all the flavor aspects of the schools. Some thing necromancy is evil. Rituals can be invented base on the schools. Wild mage and lycantrope blood has hints of transmutation. Airships which run on evocation are less effecient than ones which run on conjured fuel.
So does spell school matter to anyone but wizards in your games?