This is a new thread to discuss Eliezer Yudkowsky’s Harry Potter and the Methods of Rationality and anything related to it. This thread is intended for discussing chapter 94. The previous thread has passed 200 comments.
There is now a site dedicated to the story at hpmor.com, which is now the place to go to find the authors notes and all sorts of other goodies. AdeleneDawner has kept an archive of Author’s Notes. (This goes up to the notes for chapter 76, and is now not updating. The authors notes from chapter 77 onwards are on hpmor.com.)
The first 5 discussion threads are on the main page under the harry_potter tag. Threads 6 and on (including this one) are in the discussion section using its separate tag system. Also: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22.
Spoiler Warning: this thread is full of spoilers. With few exceptions, spoilers for MOR and canon are fair game to post, without warning or rot13. More specifically:
You do not need to rot13 anything about HP:MoR or the original Harry Potter series unless you are posting insider information from Eliezer Yudkowsky which is not supposed to be publicly available (which includes public statements by Eliezer that have been retracted).
If there is evidence for X in MOR and/or canon then it’s fine to post about X without rot13, even if you also have heard privately from Eliezer that X is true. But you should not post that “Eliezer said X is true” unless you use rot13.
About horcruxes
Magic itself seems predisposed to keeping wizards in existence, what with ghosts and resistance to blunt trauma, and Avada Kedavra requiring they be very sure about the outcome, and all that. A ritual that requires murder seems to be opposing that spirit. Can't magic make up it's mind? Or was it designed by multiple, competing purposes?
It occured to me that horcrux might be more of a late addition to magic; a hack, a twisting of an existing function. If so, the requirement may not be there for the usual reasons (to represent the making of a significant choice, as Quirrell put it), but rather as a requirement of limited resource.
What might that be? Life force? Nonsense, 'one must die for another to live' is in fact a bad non-reductionist cliché, and don't get me started on it. How about soul?
What existing aspect of magic best resembles a horcrux?
Thus I've concluded that a horcrux is the corruption of a newly made ghost; it's loaded with the state vector of the caster instead of the victim.
This gives two obvious predictions. Those killed for a horcrux will not leave ghosts. Muggles are unsuitable.
Since both predictions run contrary to canon (Moaning Myrtle and old man Frank Bryce), and Eliezer is unlikely to do that on a whim, they were adequate.
(I'm no longer sure when exacly I came up with all of the above. Pretty sure it was before the Azkaban arc.)
Chapter 71, Parvati talks about Hogwarts' '0% fatality rate' and nobody acts like it's known falsehood. Sure, it was an argument about something else, and it was narrated, not explicit, but still. How could they not know about Myrtle? Simple, there is no moaning reminder.
After this I realized I made a bad assumption (quite possibly my luckiest mistake - but never mind that). I thought the ghost creation process is subverted at the root, making the requirement check for ghosts (afraid of dying, the will to stay, or whatever it is) done on the caster. Instead, depending on implementation details, a hack may be more likely to work on what is already there; so for the ghost to be there, the victim has to have that preference.
If you don't want to draw attention to the fact that you're killing people who are likely to leave ghosts, you have to use some other criteria, and kill a lot. If only 1% of the population would leave a ghost, and you pick your victims at random, on avarege you have to kill 100 people to get one horcrux. And if you only kill the brave who dared to oppose you, it might take significantly more. Better kill their family as well. Of course, there may be ways to increase the probability of ghost as well ('the victim dying in horror'? dunno).
So this explains why mor!Voldemort's campaign was more bloody than canon, and also why smart!Voldemort didn't win quickly. Also, nerfing an overpowered spell.