Creating/researching a new spell in game, cost, timeline, result. Wizard problems...

[dehro]

Necessary context:

My character is a level 12 human wizard with serious trust issues. He is missing a chunk of his memories, lives in a Faerun that has gone through some serious crap, with very few of the canonical institutions still surviving; also, one of his party members proudly declares himself bent on eventual world domination (him being a Thay necromancer will do that to his priorities, I guess).
He feels it is his personal duty to prepare to eventually stop this party member from getting too much power and, on top of that, his passion for magical knowledge drives him to collect as much of it as he can and try to rebuild Candlekeep, which went destroyed a campaign or 2 ago, in the aforementioned crap. His personal inclination is to see every challenge as a problem to be solved by magic. He's pretty young too, barely coming of age.
He's come to the personal power level where it makes sense for him to build a home/tower.

My initial idea as a player was to somehow combine Mordenkainen's Magnificent Mansion with the spell Demiplane, in order to keep it safe and as secret as possible. However, the first can't be permanenced (which is a thing that almost doesn't exist in 5e anyway) and the second has been severely nerfed from the days of 3.5, so my character will actually have to build the place from the ground up.
My character intends to undertake a large scale project..starting out with a safe haven for himself to study, hide, recuperate...building it up to become, once the current troubles are dealt with (and he's reasonably certain he can take the necromancer in a fight), the new Candlekeep, to open to the learned/worthy public.
He doesn't have the resources or the downtime to take a year off to "Galder's tower" the place into existence so he will have to rely on an actual hired crew.

For maintenance and upkeep however, I really would like to find a way to get a staff of unseen servants, like in the Mansion, utterly obedient, loyal and also cheap labour. (:smallbiggrin:).. but that doesn't seem possible either. Unseen servant is woefully inadequate on account of duration and lack of mobility/independence, whilst the 100 servants in the Mansion are tied to that and the pocket dimension it stays in.
My character's natural response would be to research a spell that combines the two, boosting unseen servant to multiply it's effects, using MMM as a template for how to get a whole bunch of servants to last for a long time and not be restricted by my presence or the relative distance to me.

THE RELEVANT BIT.
So... as a DM, would this sound broken? what would the cost of researching this be, time and resources-wise? And what level a spell would you rate this?
I'm thinking several dozen servants who are either permanent or last 24 hours at a time... a spell that can be tied to an object in or to the house itself, so that an eventual henchman/butler/head of staff can reboot the servants when the laundry needs doing, without me having to rush home for that. Would finding a way to upcast the unseen servant be enough?

Of course, if there already is a spell that roughly does something like that, I will gladly hear of it.

[Greywander]

It kind of sounds like you want a version of MMM that doesn't kick you out after 24 hours. Is that about right? So you could just camp out there for weeks, months, or years. As with Demiplane, casting the spell is only required to enter or leave the mansion, not to sustain its existence.

Considering that MMM is a 7th level spell, and Demiplane is an 8th level spell, this sounds like a 9th level spell. Alternatively, it might be a place you create with an upcast Demiplane or MMM, and thereafter is only reachable with Gate.

If you just want more usable Unseen Servants, I might look to the Flock of Familiars spell for guidance. Instead of conjuring one, you conjure many. You want the duration to be longer, though, and you want them to have more independence and mobility. Off the top of my head, I'm thinking a 5th level spell, for something like two dozen servants that last 24 hours and can move about a large structure.

If you want to build a structure yourself, Wall of Stone can be made permanent, so that might be an option.

[Mr Adventurer]

I think you want Mighty Fortress (8th) and Mordenkainen's Private Sanctum (4th).

Edit: sorry, didn't read the OP properly. I think your main problem is that a real fortress will take at least a year to build, even before you get to staffing it.

As for your proposed spell, I'd have no problem with something like that as a DM. The servants would be tied to the location.

[dehro]

It kind of sounds like you want a version of MMM that doesn't kick you out after 24 hours. Is that about right? So you could just camp out there for weeks, months, or years. As with Demiplane, casting the spell is only required to enter or leave the mansion, not to sustain its existence.

Considering that MMM is a 7th level spell, and Demiplane is an 8th level spell, this sounds like a 9th level spell. Alternatively, it might be a place you create with an upcast Demiplane or MMM, and thereafter is only reachable with Gate..
I have given up on Magnificent Mansion because making it permanent would be a power up that requires probably a 9th level spell.
Demiplane sucks, these days, it makes having guests only possible if I am there, as the demiplane closes the door 1 hour into the spell. plus the demiplane it creates is rather tiny for what I aim to do...if I were to physically build the tower/library/house there... being already 8th level, houseruling any expansion on the initial casting would be necessarily at 9th level too.. and even the demiplane itself comes into play way too late for what I am looking for. Waiting another 4-levels to be able to upcast it is not an option.


If you just want more usable Unseen Servants, I might look to the Flock of Familiars spell for guidance. Instead of conjuring one, you conjure many. You want the duration to be longer, though, and you want them to have more independence and mobility. Off the top of my head, I'm thinking a 5th level spell, for something like two dozen servants that last 24 hours and can move about a large structure.
Once I resigned myself to building the place with stone and mortar, the focus went to the staff, and yes, your suggestion, combined with unseen servant, sounds like a good path to explore... (the combination being necessary because of the animal shapes the flock of familiars is tied to... ). Thank you for reminding me of that spell

If you want to build a structure yourself, Wall of Stone can be made permanent, so that might be an option.
I do plan to use that to speed up some of the building time, yes... if I can get the downtime for it, but my character is no architect.. he will need a master carpenter to work together with...but yes, speeding up the proces by magic is definitely going to happen. Wall of stone and Shape stone are in my arsenal for that specific purpose.

[dehro]

I think you want Mighty Fortress (8th) and Mordenkainen's Private Sanctum (4th).

Edit: sorry, didn't read the OP properly. I think your main problem is that a real fortress will take at least a year to build, even before you get to staffing it.

As for your proposed spell, I'd have no problem with something like that as a DM. The servants would be tied to the location.

The building time would not be a problem, as long as it does not require my presence there every day.. I can leave the supervision to a trusted henchman or a simulacrum or somesuch...and speed up the process with Wall of stone, when I have downtime.
So, brick and mortar it is.

At what level would you place the "flock of servants" spell? and what would you rate the cost of researching it to be?

[Mr Adventurer]

4th level, 24 hours duration. Perhaps recasting every day for a year makes it permanent.
Time and cost would be based on a fusion of the Research and Scribe Spell Scroll downtime actions from Xanathar's, plus the cost and time to finally scribe the scroll into a spellbook on top.
The "reboot" function you refer to would be a magic item that casts the spell. It would have a rarity based on items that have a similar utility 4th level spell once per day, and would need to be crafted using the Craft Magic Item downtime rules in Xanathar's.

[JackPhoenix]

You can always create undead (who require oversight due to limited initiative and maintenance by the way of spent spell slots every 24 hours), get some constructs (GM dependant on how to make them and how much it'll cost, but animated objects or homunculi shouldn't be that expensive) or bind something to fill your workforce needs. With 8th level slot (which you'll require to cast Demiplane anyway), Planar Binding will last for half a year. It's not cheap, but if you get to 9th level slots, you can just do it for free through Wish.

Considering it's FR, you can also bother relevant gods to be useful for once and send you some aid... Oghma in particular should have a vested interest in rebuilding Candlekeep.

[dehro]

You can always create undead (who require oversight due to limited initiative and maintenance by the way of spent spell slots every 24 hours), get some constructs (GM dependant on how to make them and how much it'll cost, but animated objects or homunculi shouldn't be that expensive) or bind something to fill your workforce needs. With 8th level slot (which you'll require to cast Demiplane anyway), Planar Binding will last for half a year. It's not cheap, but if you get to 9th level slots, you can just do it for free through Wish.

Considering it's FR, you can also bother relevant gods to be useful for once and send you some aid... Oghma in particular should have a vested interest in rebuilding Candlekeep.

undead are a no go for this character, as for constructs... very difficult for ingame setting reasons (this is post global war faerun, a lot of things just aren't available anymore)...
The aim would be to start building now that I am still at level 12... having to wait for level 15 or 17 won't work