I'm considering a campaign in a setting themed around undead.
The Archwitch and her undead legions conquered the kingdom. Noble heroes stood against her... and failed. That was a hundred years ago.
Now, every village has a necromancer, renting out the use of zombie labour to pull the ploughs, build walls, and chop lumber, for an exchange of some of the crops. During the night, they're kept in sturdily-built stables or in a pit with the ladder pulled up, so when control lapses they're safely stored. A tithe of the bodies of the deceased is paid to the local lord, to be used as labour or stored for future resurrection as soldiers, should war come. Those who impress the now-called Gloaming Queen are raised to unlife as vampires, given land to tend to as a shepard would his flock; keeping the wolves at bay.
Things are... stable. Peaceful, even. The laws are harsh, but fair, courts resided over by iron-masked judges. The people do not starve. When other countries cast threatening glances towards the borders, speaking of crusades and holy judgement - the corpse legions mean that there's no draft to force the peasants from the fields into war.
But a problem has emerged. Without warning, the common undead are becoming violent, breaking free of control suddenly or not being able to be controlled at all. Crops are not being harvested, quarries unmined. People are being hurt, killed, by rogue undead. Something must be behind this. Something must be done.
Enter the players; agents of the Gloaming Queen, they must discover the cause of this instability and deal with it.
Technically it'd be an evil campaign, I guess; it's lawful evil, focus on the lawful, though the players are free to be as good as they desire. Happy people work harder, and don't foment rebellion so much. It'd use at least
some of the altered weapons rules I've thought about before.