AD&D read magic

[Valiant]

What are all the circumstances a MU needs to cast Read Magic (for instance do they need to cast this before reading an MU scroll)?

 

[Thornir Alekeg]

I don't know about all the circumstances, but I know you needed it to read a scroll, and I believe you also needed it to read another Magic-users spellbook.

Edit: For scrolls, you needed to cast Read Magic the first time in order to be able to understand what the scroll says, but after that, you don't need to cast Read Magic to cast the spell on the scroll.

 

[T. Foster]

What Thornir Alekeg said. Plus, there might be other miscellaneous inscriptions or writings written in "magical script" that requires a read magic spell to decipher, at the DM's discretion. Wands or other magic items having their command words inscribed on them in magical script is something I've seen on occasion.

 

[Delta]

Quote from 1E AD&D DMG, p. 127:

Each scroll is written in its own magical cypher, so to understand what sort
of scroll has been found the ability to read magic must be available. Once
a scroll is read to determine its contents, a read magic will not be needed
at a subsequent time to invoke the magic. Note that even a map will
appear magical until the proper spell is used. Reading a scroll to find its
contents does not invoke its magic unless it is a specially triggered curse.
The latter scroll appears to be a scroll of any sort. It radiates no evil or
special aura beyond the magical.