FAQF Workings of the Marauder's Map

[Martin Smith]

No: HPFGUIDX 23511

--- In HPforGrownups at y..., prefectmarcus at y... wrote:
> How do the dots work?
> 
> I have always thought that the dots only show what might be of 
> interest to mischief makers.  To wit, a teacher safely in his or 
her 
> sleeping quarters is not a threat, but a student or ghost wandering 
> the halls who might stumble upon them is.  If the map showed the 
> location of everybody in the castle all the time, it would be 
> information overload.  But if it only showed those out-and-about, 
it 
> would have meaning.  
> 
> Marcus

Absolutely my idea! Think of the map as an AutoCAD drawing, with 
different layers (for instance, roads is one layer, houses another 
and height coordinates a third). These layers can be switched on and 
off depending on what you're currently working with.
With this analogy, MM has different layers for teachers/students at 
sleep, those out-and-about (as stated by Marcus), house-elves at 
work, caretakers roaming the corridors etc. The map's default layer 
settings are to show those who can interrupt the mischief-making, 
which is all fine by the Marauders (and later, the Trio), but if you 
at some point needed to find someone specific, say Dobby, you could 
just switch off all layers but the House-elf layer, and Bob's yer 
uncle!
(Hey, I just did a >10-liner "Me too!")

Mr Smith, ground design engineer