The more I look at spell schools, the more I notice that Divination seems to be severely underdeveloped and mechanically overspecialized, while also suffering from too much overlap with other schools, leaving it lacking. It basically appears to be a dump school. I suppose this wouldn't be much of a problem, except for the fact that Wizards are capable of specializing in it, even though the wizard divination spell list is unusually small for them.
I get that the main focus of Divination is to reveal or otherwise obtain information. That much is pretty clear. But if you take a look at the Message spell, which seems to be a prime target for Divination, it's...Transmutation? What exactly are we transmuting here? How is this that different from the Telepathic Link spell, which is Divination, apart from being lesser in effect and not a direct mental link? It certainly can't be the lack of mental link that disqualifies it as Divination, as spells like Scrying don't require that.
Speaking of Telepathic Link, if you consider that along with Tongues and Comprehend Languages, it's clearly apparent that Divination spells are capable of connecting directly to the mind, as well as manipulating information. Doesn't that sound right along the lines of Modify Memory? But, that's Enchantment!
Ok, so maybe it's purely meant to interpret and collect information, dispelling mysteries. True Sight seems to emphasize that, as it offers a hard-counter for Illusion and shape changing magic. But wait, countering and defending...isn't that basically Abjuration's whole shtick? Further, even if Divination were meant specifically to counter Illusions, why does the Illusion school offer a hard-counter for Divination in the form of Arcanist's Magic Aura?
Alright, let's set aside all of that for now. Time to approach it from a different angle. Health is supposed to be a representation of physical and mental state. This makes sense, given that the Divination spell Contact Other Plane can result in your taking significant psychic damage and going insane if you fail an intelligence save. Clearly, intellectual damage can be done to your mind. So why are there no divination spells that weaponize that? Direct damage and healing is clearly not Evocation-specific, but for some reason even though that is partially mental, Divination plays almost no role.
Ok, so maybe its main combat mechanic is on providing temporary advantages for otherwise normal actions. True Strike and Guidance seem to follow that theme. But, then, Bless is mechanically just an upgraded Guidance, and it's...Enchantment?
Even if we consider information planting, suggestion, and manipulation, these are all gobbled up by Enchanting and Illusion. Even the persuasion skill offers more in this department than Divination.
Ok, so let's set aside the fact that there's seemingly not much consistency throughout the divination spells aside from "ask a question, get an answer", which isn't nearly enough to justify the Divination-spell-specific feature of the Divination wizard except for maybe the special case of a constantly politics-heavy campaign. About the Divination Wizard, the Portent feature is particularly fascinating. According to description, when you use this skill, it's that you've already seen a vision of the outcome of that action. Fortune-telling, basically. You're not influencing it, supposedly. But then, you could also use a Divination spell to ask a god a question about a future action's outcome, and get a "truthful" response...and then deliberately change it with Portent. That means by these descriptions, one of them has to be wrong. Either the entity lied, or it's possible to use Divination magic to change the future. Speaking of, if you know about the future, wouldn't you be able to change it anyway? The Divination spell I just referenced seems to imply that, saying that it doesn't take into account circumstances that might change the outcome. So, then, it's possible to change the future, you can use Divination to learn the future, and apparently to aggressively change it to suit your whims as well. And yet aside from Portent, we don't see this come back up?
It seems like WotC should maybe have rethought their school definitions and capabilities sometime around when they designed a spell that literally shared the exact name of one of the schools (Divination).
What gives? Is there actually some exact definition of what the capabilities of the school of Divination truly are? Or is this just an artifact of poor design, allowing other schools to step on Divination's overly-specialized toes?
My main reason for asking this is because the list of Divination spells is so small and overly specialized. It would be nice to know if there's any official thematic guidelines to guide the homebrewing process when creating new Divination spells, should the opportunity arise.