Time for another nitpick of the Dungeons & Dragons basic set from 1978. Did you know that this ruleset allows magic-users to cast cleric spells? OK, it lets M-Us cast the equivalent of certain cleric spells from scrolls, but that got your attention, didn't it?
How does this work? The Scrolls subsection of the TREASURE section of the book lists, in addition to the selections for a cursed scroll and various protection spells, entries to pick "Any potion spell" with a couple of exceptions, "Any ring spell" (likewise), and "Any wand spell." So there's a chance your magic-user could find--and use--a scroll with a spell of Healing based on the potion or staff, the magical equivalent of the clerical Cure Light Wounds spell.
Of course, a good rules lawyer could argue that the Holmes scroll rules encompass all cleric spells as well. Here's how: some of the other entries for the type of scroll are "Any one spell," "Any two spells," or "Any three spells." And here's where it gets interesting. In the EXPLANATION OF MAGIC ITEMS regarding scrolls, Holmes instructs the dungeon master, "Select the spells from the appropriate list by some random method." Therefore, I would roll a to see which book of spells the scroll contains, M-U levels 1-3 or clerical spells levels 1-2, and then roll to see which spell. You might argue that since Holmes allows only magic-users to read scrolls (other than protection scrolls), the "appropriate list" means only magic-user spells, I read "appropriate" as the lists mentioned in the table: character spells, potion spells, ring spells, and wand spells.
What about elves? I'd argue that since "Elves progress in levels as both fighting men and magic-users," they can use magic scrolls.
Which reminds me--according to Holmes, "The spells written on the scrolls can be read only by magic-users, except for the protection spells." If we interpret that strictly, that means that only M-Us (and elves, who progress as M-Us) are affected by cursed scrolls.
Your thoughts? Would you run a game this way, with cursed scrolls only affecting magic-users? What about scrolls with clerical spells? Allow them at all? And if you do, allow clerics to use them, or only magic-users?
Or am I the only one who thinks about these things?