I have been trying to answer the riddle but can't get the game to recognize quotation marks. I saw an earlier forum that said to use the key mapper, but can't understand how to use it.

Did you use single or double quotes? I don't have the GOG release of the game, but in the one I do have both say "word" and answer "word" work for me.

Edit: Or is it typing the quotation marks that's causing trouble? I guess that could be an issue in DOSBox, if that's what GOG is using...

In the Lost Treasures version of Zork II, nothing seems to happen to me if the Wizard casts the Fantasize spell on me. Whatever happened to the interesting fantasize items such as the following:
pile of jewels
gold ingot
basilisk
bulging chest
yellow sphere
grue
convention of wizards?
Or was all this fantasize stuff removed in the Lost Treasures release?

Probably not deliberately.

Running the data file for Version 48 through txd (a Z-code disassembler) does show those texts. But judging by the recently leaked Infocom source code, the hallucinations were printed by a special case in the function that (if I understand it correctly) prints the contents of an object (PRINT-CONT). And I don't see anything like that in the disassembled file in this particular versions, while I do in others. (I'm making the assumption that the functions are in at least roughly the same order in all versions.)

Maybe this special case was accidentally lost when they upgraded the game to use a more modern version of the text parser? (E.g. earlier versions didn't recognize "z" as an abbreviation for "wait".)

Thanx for the suggestion.

Where did you see the source code? The last source I saw was the 1979 DEC 10 Muddle source...

A few weeks ago someone released the source of all Infocom games (probably part of that internal shared drive data that someone got hold off round 2007 or so but never fully made public). There's a GitHub account that collected this and the source of other historical games, each in its own repository. Here's the one for Zork II, and it's a bit newer then the Muddle source https://github.com/historicalsource/zork2

Very interesting, thanks!

Also very interesting, thanks for that! It's nice people are actively doing things with the source.

Wow, there's a *lot* of stuff there.

Now that it's pretty much confirmed that the Fantasize spell doesn't work in Version 48 (Lost Treasures version), is it in any way possible to obtain an older version (e.g.: where "z" is not recognized as a shortcut for "wait") so I can, for example, see what happens when I'm in the Oddly Angled Room under the Fantasize spell? If not, I'm somewhat frustrated and disappointed.

It's possible in the sense that the files still exist. Legally, I guess it's a gray area, but hey - you already bought the game at least once.

Andrew Plotkin has created an "Obsessively Complete Infocom Catalog" of all versions of Infocom game files and source code still known to exist. Whether or not all of them work is a different matter. Some were not publicly released, so they may be incomplete, damaged, or otherwise buggy. (For instance, I believe the unreleased version 63 of Zork II tried to reinstate the Fantasize spell, but didn't do it correctly.)

The Infocom Fact Sheet is another attempt at cataloguing known versions (without including the actual files), but it hasn't been updated in a long while. Still, it may give an idea which versions were official releases and which were not.

Success, sort of. The Fantasize spell works in Version 23. However, nothing unusual seems to happen if, as suggested in a "For Your Amusement" section of the eristic.net Zork II walkthrough, I wander around the Oddly-Angled Rooms while under the influence of the fantasize spell. Mixed eureka and disappointment. Maybe I need to explore an even older version of Zork II to get the oddly angled room fantasy?

Just for fun, I also downloaded and tried the unreleased Version 63. One bug is that it doesn't recognize the word "point", so with some help, I found an alternate verb: "wave" in order to "float" the menhir with the wand.

Update: Nothing happens, in any of the older versions of Zork II, if I'm "fantasize"d in the Oddly-Angled Rooms.

Awhile back, I posted the following on the Tvtropes Unwinnable By Design / Infocom page:

"The Zork II hint book indicates two ways to move the menhir. It doesn't mention that one of those ways makes the game unwinnable. If you ask the demon to move the menhir, then you can't get the Wizard's magic wand, which is required to win the game."

Later on, someone amended my comment with the following:

"Although this only applied to later versions of the game, and in the earlier ones getting the demon to move the menhir was a valid solution."

So I went to the The Obsessively Complete Infocom Catalog, downloaded and played all the old versions prior to version 48 and found that I misunderstood something. The wand is required in the endgame in all versions.

Aside from exploiting the Version 7 bug mentioned in Graeme Cree's Infocom Bugs List, in all the old versions prior to v48, (spoiler alert!) you can actually ask the demon to both kill the wizard and move the menhir in one concatenated command. Aside from these, if anyone knows of another way to get the wand, please post.
Of course, from and including v48 on, asking the demon to move the menhir is a trap, similar to putting the lore book in the slot in the puzzle room in Zork III or using the Kulcad spell in the wrong place in Enchanter.

Maybe the hint book statement "In later releases (revisions) of the game, the landing is guarded by magical runes" is misleading.