Or has Dumbledore found it so useful to carry a large rock around that "get a big rock, keep it with you at all times" is in the top five things he'd tell his younger self if he ever got the chance? Seriously -- the fuck?
The obvious interpretation of this is that spellcasting is a skill like any other, and practice develops it. By giving Harry an implausibly large object to carry, and then having him interact with the Transfiguration professor, Dumbledore can be fairly confident that Harry will try to transfigure the rock into something more reasonable to have in constant physical contact with him. This constant transfiguration practice will help Harry level up his abilities, and a huge rock is predictably useful in combat situations.
Here's a short list of rules violations:
He also showed off his unique partial transfiguration trick during combat, which Dumbledore was hoping he would save for the Final Battle.
Only if they autopsy the troll and figure out it was transfiguration and not something else. But I'm pretty sure Quirrellmort already knows Harry can do that.
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 88-89. The previous thread has passed 500 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.
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: