I looked at the forums sffworld and coolscifi as well as this discussion area but could not find the answer...

It is clear that Dumbledore created the mirror at the end of the Sorcerer's Stone and obviously Fluffy was Hagrid’s addition to the obstacles Harry (Hermione and Ron) had to work through but what about the other obstacles?

Which Professor created which obstacle?

  • 3
    (-1) This question does not demonstrate the first requirement for asking questions: scifi.stackexchange.com/help/how-to-ask
    – RyanS
    Commented Jul 15, 2014 at 19:45
  • I added that....
    – Jim
    Commented Jul 15, 2014 at 19:53
  • @Jim For future reference, where did you look? We don't know what those "several places online" are.
    – Izkata
    Commented Jul 15, 2014 at 23:05
  • @Izkata I did that also.
    – Jim
    Commented Jul 16, 2014 at 15:57
  • @TankorSmash I made the changes...
    – Jim
    Commented Jul 16, 2014 at 18:57

4 Answers 4


Hagrid tells us which teachers are contributing protections:

“Well, I don’ s’pose it could hurt ter tell yeh that… let’s see… he borrowed Fluffy from me… then some o’ the teachers did enchantments… Professor Sprout – Professor Flitwick – Professor McGonagall –” he ticked them off on his fingers, “Professor Quirrell – an’ Dumbledore himself did somethin’, o’ course. Hang on, I’ve forgotten someone. Oh yeah, Professor Snape.”

— Chapter 14, Norbert the Norwegian Ridgeback

This makes it a simple process of logical deduction and elimination.

Midway through the chambers, Hermione lists those which they’ve encountered so far (just after they’ve finished the chess game).

“What do you reckon’s next?”

“We’ve had Sprout’s, that was the Devil’s Snare – Flitwick must’ve put charms on the keys – McGonagall transfigured the chessmen to make them alive – that leaves Quirrell’s spell, and Snape’s…”

— Chapter 16, Through the Trapdoor

At the very next obstacle, they encounter the troll. The chamber after this has the logic puzzle involving the potions, so this is clearly Snape’s work.

By a process of elimination, we can deduce that the troll is Quirrell’s doing, or just wait for Quirrell to admit it in the final chamber:

Certainly. I have a special gift with trolls – you must have seen what I did to the one in the chamber back there?

— Chapter 17, The Man with Two Faces

Finally, as you said, Dumbledore provided the mirror of Erised.

So the protections were as follows:

  1. Fluffy – borrowed from Hagrid
  2. Devil’s Snare – planted by Sprout
  3. Flying keys – charmed by Flitwick
  4. Wizarding chess – transfigured by McGonagall
  5. Mountain troll – set up by Quirrell
  6. Logic and potions – cooked up by Snape
  7. Mirror of Erised – designed by Dumbledore
  • 1
    Yes, "special"... ;)
    – Izkata
    Commented Jul 15, 2014 at 23:09
  • @alexwlchan, But wasn't part of the Flying Keys done by Madame Hooch as she is associated with brooms.
    – Pobrecita
    Commented Jul 16, 2014 at 20:06
  • @iliveunderawesomerock: That would make sense, except Hagrid doesn’t list Hooch as one of the teachers providing protection to the Stone.
    – alexwlchan
    Commented Jul 23, 2014 at 22:07
  • @alexwlchan true. But who did the brooms then. Or is that not canon.
    – Pobrecita
    Commented Jul 23, 2014 at 22:30
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    @iliveunderawesomerock: Is there anything to suggest that the broomsticks in the flying keys room are anything but ordinary broomsticks? Do they have any special enchantments?
    – alexwlchan
    Commented Jul 23, 2014 at 22:50

Hagrid: Fluffy

Sprout: Devil's Snare

Flitwick: Keys

McGonagall: Chess

Quirrell: Troll

Snape: Potion Puzzle

Dumbledore: Mirror Erised


I believe that this was answered in the book as the three went through each obstacle, but I might be wrong. I don't have a copy of the book near me.

Here is what HP wiki says, which makes sense:

After that, the Stone was placed in a special chamber and guarded by seven enchantments and creatures, provided by the professors at Hogwarts: Professor Sprout's web of Devil's Snare; flying keys, charmed by Filius Flitwick; a life-size board of Wizard's Chess, transfigured by Professor McGonagall; Professor Quirrell's mountain troll; Professor Snape's potion riddle; and the Mirror of Erised, placed there by Albus Dumbledore. Hagrid's massive three-headed dog, Fluffy, guarded the trap door through which the chamber lay. In order to keep them safe from Fluffy, Dumbledore forbade the third-floor corridor to all students.


Actually, it is quite obvious to any person who has adequately read the book, that it was Professor Flitwick who made the Wizard's Chess game, and Professor McGonagall who created the obstacle of catching a flying key. These keys are not completely transfigurated, but there is no known charm that Professor Flitwick could have performed to attach wings to the keys. Another reason; the game of Wizard's Chess was not transfigurated, but rather enlarged using the charm Augeo. Not to be confused with the Engorgment charm, Engorgio.

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    Can you cite any text from the book to substantiate your answer? Commented May 28, 2016 at 20:07
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    Sorry, I seem to have made a mistake. I should have checked the book. I realize that I said that anyone who had adequatly read the book, The Sorceror's Stone would have known, and I've read it 6 times, but I didn't check the book. I'm afraid I was being a bit cocky. Commented May 29, 2016 at 12:46

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