You guys get your tickets?
Just what it says on the box: it’s a method for talking to the dead, using old lottery tickets. This particular technique is particularly good at getting information involving money or valuables; someone looking to find out where Aunt Edna stashed the savings bonds before she died will find necrolottomancy extremely helpful. It’s much less so for basic communication with the missed dead; but there are other and far less problematical spiritualist techniques for dealing with that sort of thing.
Necrolottomancy sort of works like a Ouija board, except that the spiritualist using this particular method of divination has to come up with his or her own unique style. There are a bunch of broad techniques, but no one standard method of necrolottomancy: some diviners draw an elaborate overlay over an existing ticket, others laminate an entire set of tickets and use them like Tarot cards, a few burn the tickets and use the ashes to facilitate ‘speech’ between them and the dead. The important thing is that lottery tickets be used somehow.
Oh, and that something dies in the process. Don’t worry, it doesn’t have to be a person or anything. Even ripping up a houseplant will get results. But, ah, insects work better than plants and mammals work better than insects and humans, well, hoo boy but a human sacrifice really gives necrolottomancy some juice. Everybody who can do this particular divination knows it, too; which is why the diviners who can do it often refuse to admit that they can do it, because there are a lot of people out there of dubious moral character who would be happy to stab a random bum if it meant being able to find out what happened to the money. Or the lost shipment. Or why the deal went sour — well, one gets the idea, surely.
And yet, necrolottomancy is not permanently banned, by those who are in a position to do such things. It’s not favored, and God help anybody who gets caught sacrificing a human being, but it’s not actually banned. Sensible diviners might be well-advised to avoid speculating too much as to why.