The Marauders found every secret passage out and into Hogwarts and every shortcut, hidden passage, and hidden room in Hogwarts, how did they miss the Room of Requirement?

3 Answers 3


It's possible they did.

It's possible they never had need for the Room of Requirement. The one time that I can think of that they might have needed the Room of Requirement is when Lupin needed a spot to hide his Werewolf problem, but Dumbledore figured that out for him.

"But then Dumbledore became headmaster, and he was sympathetic. He said that as long as we took certain precautions, there was no reason I shouldn't come to school..." Lupin sighed, and looked directly at Harry. "I told you, months ago, that the Whomping Willow was planted the year I came to Hogwarts. The truth is it was planted because I came to Hogwarts. This house" - Lupin looked miserably around the room - "the tunnel that leads to it - they were built for my use. Once a month, I was smuggled out of the castle, into this place, to transform. The tree was placed at the tunnel mouth to stop anyone coming across me while i was dangerous."
- Harry Potter and the Prisoner of Azkaban, Chapter 18 (Moony, Wormtail, Padfoot, And Prongs)

Another possible explanation is that they did know about it but couldn't put it on the map because it is unplottable, and the room has rules.

The beauty of the Room of Requirement was that it adjusted to nuances. Even the Marauder’s Map couldn’t tell you who was inside it.
- Everything you need to know about the Room of Requirement - Pottermore

To me this quote means that even if the Marauders did know about it it was protected magically against being put on their map.

  • 2
    Wouldn’t you know, Padfoot? :P
    – Obsidia
    Oct 2, 2018 at 1:25
  • 5
    my memory is grey after falling through the veil...
    – Niffler
    Oct 2, 2018 at 1:26
  • 4
    Sorry about that...
    – Obsidia
    Oct 2, 2018 at 1:27
  • 4
    Somehow I have trouble imagining Bellatrix being sorry for Padfoot.
    – Orlahm
    Oct 2, 2018 at 9:35
  • It is not necessarily true that the Marauders could add things to the map (which was probably a part of the Hogwarts security system that they were able to hack and gain access to).
    – Mathaddict
    Oct 2, 2018 at 19:54

Purely speculative in-universe explanation: They never needed it.

Purely speculative out-of-universe explanation: The room was not conceived until after Prisoner of Azkaban was sent to the publisher.

  • IIRC, Dumbledore mentioned earlier in the series finding a room full of chamberpots on his way to the toilet, and being unable to find it afterwards. That sounds an awful lot like the Room of Requirement. Oct 2, 2018 at 18:02
  • 1
    @DavidThornley That was in The Goblet of Fire: "The first mention Harry Potter heard of this room was in 1994, when Albus Dumbledore told Igor Karkaroff of his discovery of a room full of chamber pots when he needed to go to the toilet" harrypotter.wikia.com/wiki/Room_of_Requirement Oct 2, 2018 at 18:30
  • I guess this establishes that the Marauders never needed a potty break while they were sneaking around the castle.
    – EvilSnack
    Oct 3, 2018 at 3:12

It would not be especially troublesome if the Marauders had never found the Room of Requirement. If you don't know about it, the only way to find it is pretty much sheer dumb luck. To quote the original description of how to access it, from Chapter Eighteen of Order of the Phoenix:

"Dobby said to walk past this bit of wall three times, concentrating hard on what we need."

Apparently, then, there are three conditions to accessing the Room of Requirement:

  1. You must be in front of the wall.
  2. You must concentrate on what you need.
  3. You must walk past it three times.

The odds of these three things converging together by accident would seem to be pretty small. While it does seem that a few people (e.g. Dumbledore and Filch) may in fact have stumbled upon it by accident, there doesn't seem to be any reason to think that this would be likely to happen to any given person – even someone who spends a lot of time exploring the castle. In fact, Voldemort assumed that he was the only one who had ever discovered it. From Chapter Twenty-Seven of Deathly Hallows:

As for the school: He alone knew where in Hogwarts he had stowed the Horcrux, because he alone had plumbed the deepest secrets of that place...

Additionally, it is perhaps arguable that even if all three conditions are met, the room will not necessarily show itself. Dobby says:

Sometimes it is there, and sometimes it is not, but when it appears, it is always equipped for the seeker's needs.

Depending on how you understand the first four words of this quote, it might mean that even when you do properly seek it, it will only be there sometimes.

Either way, it is entirely reasonable, even expected, that even though they "found every secret passage out and into Hogwarts and every shortcut, hidden passage, and hidden room in Hogwarts" they would not have found the Room of Requirement.

  • Out of curiosity, how do we know Filch found it? I remember Dumbledore and the toilet thing, but Filch?
    – Jenayah
    Oct 3, 2018 at 1:48
  • 1
    @Jenayah Dobby mentions it: And Dobby knows Mr. Filch has found extra cleaning materials there when he has run short, sir, and –" Unclear, though, if it was accidental or not.
    – Alex
    Oct 3, 2018 at 1:49
  • Okep, thanks for the info :)
    – Jenayah
    Oct 3, 2018 at 1:53
  • @Jenayah No problem. I was originally going to include the quote in the post, but I thought it would needlessly distract from the point (as it is kind of a side point).
    – Alex
    Oct 3, 2018 at 1:54

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.