I'm planning a campaign loosely where players have to fight enemies backed by a larger, scarier empire that frequently sends out their agents to try to assassinate them while they try to setup a new kingdom post-revolution (think the beginning of Game of Thrones where players are on the Small Council, but they're also sort of Danaerys trying to fend off the spies and assassins of the enemy kingdom's Varys).
I want there to be a lot of cloak and dagger stuff. The players will probably have to protect themselves and fellow members of the court, the monarch (whether it's a player or NPC), allied diplomats, and such from assassins while also rooting out spies. Those resulting battles, along with adventures that I'll incorporate with diplomatic missions abroad, are what will make it DnD.
But it occurred to me as I was planning the worldbuilding for this campaign that a lot of the danger of assassinations will be lost if they can be undone by resurrection magic. Then I started wondering how kings, organization leaders, criminal syndicate bosses, basically anyone important ever dies in any high fantasy DnD world. For players I can restrict their access to diamonds or whatever, but for NPC's who are rich and powerful, not sure if that makes much sense. Besides, it's okay of players have access to the magic, but I want NPCs to be threatened by it, because it adds drama and stakes to the story I'm planning. But if players have access to it, then basically no NPC around them is in danger either, and I lose a lot of the tension I was counting on.
So looking for advice on how you would solve this. Tl;dr: How would anyone important or rich die in your fantasy world from stuff that are not old age? (assuming you want a fantasy world like I do where death is a dangerous possibility)
Restrict the resurrection spells? Restrict diamonds even more so they're rare even for kings? Manipulate the religion or cosmology of your world somehow? Do something with the resurrection spells themselves, like like Matthew Mercer's optional rules? Something else?
I've been plotting out some ideas for what is essentially the inverse of your campaign for some months now. My players will be an elite group of saboteurs and seditionists sent to the capital city of some evil empire in order to bring it down from the inside, however best they see fit.
I ran into the same problem you did. If this empire is ostensibly so powerful, wealthy, and influential, then why couldn't they just resurrect anyone important?
I realise it's not quite as exciting as the other answers, but ultimately I did decide that I'll just heavily restrict the resurrection spells. Resurrection will be theoretically possible, but in the setting, the only known way of accomplishing it is with a powerful and limited-use artifact locked deep away within the empire's vaults. Destroying it or stealing it would be a very good avenue for the players to pursue in order to destabilise the establishment.
On the players' side, should I ever actually get the campaign off the ground, I'll tell them that resurrection spells will not be generally allowed to pick for level ups. I think I would be ok with them spending significant time and effort, maybe a chain of quests, to discover the spells themselves if that's what they're truly interested in and think will advance their cause, but with the warning that if word gets out it will paint a massive target on their backs since that kind of power could completely reshape the worldwide political landscape.
Hopefully, in addition to solving the problem of making sure their high-profile assassinations actually stick, this policy would also encourage the players to play a bit cautiously and generally keep the stakes high.
Anyway, all this to say, shaping the rules and lore of your world to more precisely fit the experience you are trying to provide makes a lot of sense to me, and is worth considering. As long as you get buy-in from the players up front, of course. Good luck with it!
Thanks! It's also an interesting idea. I could imagine the evil emperor keeping the limited use artifact in his vaults being saved only for him if he dies before an heir, or for a future heir to use otherwise.
Players could even obtain a similar, limited use magic item in that kind of campaign. Like the equivalent of Scrolls of resurrection would be an amazing, treasured reward from dungeons and quests if there's no other way to learn resurrection spells.
Also, good luck with your campaign, too!