Consider that the school is full of 11-18 year olds with access to weapons of mass destruction and it seems to me that the apparent safety of the place for the past 50 years is due to luck rather then anything inherent in system.
Perhaps luck is inherent in the system. The canon storyline does include a literal luck potion, so similar things are plausible. They also have and use a seer, and short-range time travel. The latter two could be used in ways that prevent deaths without a corresponding reduction in close calls.
Ya, If current generation wizards can brew a potion of luck then why not an ancient ward of luck? Sounds reasonable to me.
(The HPMOR discussion thread after this one is here.)
The previous thread is over the 500-comment threshold, so let's start a new Harry Potter and the Methods of Rationality discussion thread. This is the place to discuss Eliezer Yudkowsky's Harry Potter fanfic and anything related to it. The latest chapter as of 09/09/2011 is Ch. 77.
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: one, two, three, four, five, six, seven, eight. The fanfiction.net author page is the central location for information about updates and links to HPMOR-related goodies, and AdeleneDawner has kept an archive of Author's Notes.
As a reminder, it's often useful to start your comment by indicating which chapter you are commenting on.
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: