Nothing but the time and the name by which the time knows us.
In this universe truth and time are interwoven, they are the same thing. Kingdoms rise, kingdoms fall and species change one another as the world goes on: each particular place or entity is many things but only the time tells us which of them exists in relation to the rest. The essence of time is of separation of one truth from another. In mortal life the living break apart as the time notices their place in history more and more.
Memory of living is a fickle thing. Records are full of lacunae and chronicles are falsified to please too many petty kings. The world itself is mostly unaware of the time - ever-young, it peacefully yokes under its passage like a dumb animal under the hand of its master - and thus offers no help. If you wish to know the untainted truth of past, of present and of future you need to ask the time.
You ask the time through the dead. Dead are the only connection between it and the mortal perception, they are the only ones who have capacity to understand both mortal concerns and the truth of time, thus bridge them together. Moreover, the living are creation of unity and connection, not of the separation - direct touch of the time hollows the living out, breaks them apart and disintegrates them. In a sense of the living, many of such mortals never existed although in truth their numbers are significant.
Proper dead are pure conscience, identified only by the name by which the time knows us so it can separate us from the rest. Such dead are free and mostly silent. Such dead can observe any moment in time, and they do, and they did, and they will. Such dead are also rare comparatively to the rest of the newly dead because to die this way not only the soul much be taken but every single memory must be hollowed out of the living and their body must not form any new memories before they die. It isn't an easy task to accomplish and such dead are mostly created for important oracular purpose by mortals.
Proper dead are open to the time and its truth in its fullest - a conscience free to observe any truth without a need to influence it, without an ability to remember it, without earthly desires to meddle with it and without any means to do so even if they wished. In a sense, they are the time: such dead possess almost full omniscience and nothing but it and the name by which the time knows us.
You won't ever feel it but any moment of time is full of the dead, gossiping endlessly about living. You cannot hide from them any better than you can hide from the time itself.
The time does not disintegrates those dead as it does the living, but eventually they can be set free.
But metaphysics of the time concerns the living little, their purposes are practical. Many of the living want to know the time for power, out of fear quite often and in curiosity the least. And even the curiosity often ends as serving either fear or power.
The living can ask the dead in two ways: they can either prepare the proper dead (leaving it with just a couple of memories so it retains the ability to communicate the sought answers before it is fully free) or they can attract attention and ask the choral of gossiping dead if the sought answers are not too far.
In both cases the seeker has to temporarily die as no spell and no miracle can help the living see and speak to the dead. Some seekers have a talent to die temporarily, for others there are medical ways to return back to live before the body goes to soil. Still, it is always useful to have a healer at hand.
To attract attention of improper dead, the seeker has to know the name by which the time knows us, the particular name for the specific dead - otherwise they are going to get the full gossiping choral and no means to distinguish one truth from another. Such names are never fully known to the living and even to the improper dead themselves, but what helps is that they start with mortal name and life. The more details of mortal life the seeker can recite in summoning, the better they attract the attention of this particular dead and no others. Most common is a tradition to supplement the name by staging (honestly or theatrically) of important events from the life of the sought dead - it sets the small beacon through the time for this particular dead much stronger than just recital.
Some cities keep libraries of long scrolls with deeds and life details of deceased so they can be summoned predictably to give answers; in other parts of the world illiterate tribes recite such deeds orally and keep the records of their ancestors alive through generations and songs. Often those are the most honest chronicles among the living.
Improper dead have limited capability to travel from the time of their lives - as living world moves farther and farther away into a present, such honoured dead are often forgotten after a century or two of service or consulted only in the matters of their tethered past as they no longer can see the future.
As future dead are not known to the living, questions about far future can be asked in two ways. One way is of far-faring dead who is almost proper but they are almost the one with the time so their language will not be fully understood. The second way is to learn the names of future dead from the improper dead of present and then learn the names of even later future dead from those, groping for the future names a step by step. People without a talent to die temporarily will find the first way easier despite the difficulty of communication.
And it is not easy to communicate with proper dead. For the living their answers are always lacking in sense and clarity although for the dead themselves they are crystal clear and always true. It is not easy to communicate with improper dead for their understanding of time is muddled by their own tethers. But if you wish to know the time you have no other choice because only the dead can know the truth.
- Too long-winded, I think, and barely usable. It can be, basically, summarized as a) only dead can travel through time and see what really happened/going to but even they cannot interfere with it b) the less memories the dead have the farther they can travel from their own time and less comprehensible they become until they reach full omniscience and therefore full non-communication c) to summon the dead you need to know their history, the more the better, or you'd get either a noise or silence; d) the seeker has to die to communicate with dead and be able to return so the whole thing is not fully useless e) some people have a special talent of dying temporarily but with proper healing/medical attention it can be done for other people as well; f) the living cannot fully comprehend the time always seeing it as linear in some way; the dead can come to fully comprehend the time but they'd probably speak pure math at this point.
Can the living change the future with the information from the dead? Depends on how much you believe in the fate. The default setting for this world is that 'yes, you can (with effort) but in doing the new timeline becomes the only timeline - it was always been this timeline; if the paradox is going to be created it is the "self-fulfilling prophecy" kind.
Alternatively you can set the setting in such way that asking about the future creates this future (so a prophesy always wants to fulfil itself) and people can battle each one with prophesies to see which future is going to win.
Time travel for the living is not possible and dead cannot affect the world by anything else than information. Mostly the dead don't even want to.
- I wanted to have necromancy that actually mean necromancy, i.e. divination of death albeit in a less gory way than with innards of a goat. The divination here has a lot of recital of deeds and performances, where people imitate the history by staging this or that event to attract this or that dead person. By "honest staging of events" I mean the engineering of history - somebody can try to intentionally recreate this or that drama, this or that war to summon a long-ago dead.
The goat can be added back if you so wish.
The DnD necromancer in this world would probably be an animator of bodies and constructor of golems, kind of like a necromancer in "Diablo 2" - pure matter, nothing ethereal, great student of anatomy, dollmaking and tailoring.
I also wanted a necromancy that can be as clear or as muddled as I wish - and I can have a lot of fun with improper dead, as they might retain earthly personalities or be slightly off, or be very much off-kilter.
The main barrier to communication between the dead and the living is language/perception, not the necessity for the seeker to die a bit. The dead view a lot of things much more differently than the living - we move freely in space but unwillingly through the linear time; for the proper dead it is probably the opposite and the improper dead are in transition.
Prophesies tend to be vague and symbolic. Maybe this is why: the dead and the living just see time differently and cannot communicate in the same terms.
- The intentional creation of proper dead is a quite grim process.
- The first connection of time and death for me was in ADnD 2nd edition where wrights (I think) had ability to age people, and haste spell did the same for each use. Those things were dropped or glossed out in later editions but I was kind of wondering why time and dead were always connected in the earlier ones.
- I wasn't writing it with 'Planescape' in mind but it might be used for Dustmen, I suppose. Goes with all their 'leave the earthly pleasures and aim for undeath, death and transcendence' theme. Dustmen can be those people who have a talent to temporarily die.
- I don't really see it as a player class, more like a setting aspect, but if I had to create a necromancer, they'd have a 'talent to die temporarily', and be very knowledgeable in lore and theatrics. Depending of how mutably you define the future, such necromancers could be creating self-fulfilling prophesies for their benefits or just be in the right place in the right time with the information from the dead. They will also make excellent spymasters, information brokers and treasure-hunters.
- It builds on the previous limitations. In the world there soul is not often destroyed and memories are not a magical commodity the dead will probably just go to afterlives or stick around as common ghosts.