IIRC, though, it may render the game unwinnable to do this. I read this is by design; to illustrate how wishes are unrereliable and how it’s preferable to just “put in the work” instead of wishing.
Deep world building… magic system, sort of… Well, if you are willing to download a TADS interpreter for best experience, “According to Cain” is not strictly fantasy but it’s fairly deep. It’s a biblical setting. It doesn’t have a “magic system” like Enchanter or Spellcasting 101, but it has a system that feels like magic. It can be a bit overwhemling overwhelming for new players, maybe, but on the other hand it’s also got a few features that lessen the burden.
I have yet to play “Worlds Apart” but it seems to consistently rank highly in terms of world-building. “Blue Lacuna” also seems to be a place you can lose yourself in.
A fantasy-setting comedic-style unusual parody with no magic system but magic items is “Adventurer’s Consumer’s Guide”, I think it may fit your bill only very tangentially but you may find it enjoyable. Or not.
An example of a non-fantasy-game magic-system-type-of-thing is Savoir Faire, worth experiencing. And what Counterfeit Monkey does is surely some kind of magic!
EDIT - “Bliss” is a fantasy game. I am not sure that I can recommend it or say it’s good, but I can tell with certainty that it’s a game I never forgot.
EDIT - Interestingly enouogh, IFDB may have you covered: IFDB’s search for “Fantasy”. Checking the higher-rated games on this list, some of which have been mentioned in this thread, is a great way to get started, though some of them aren’t “fantasy” in the “kingdoms, swords, sorcery and goblins” sense. The very first item, “Hadean Lands”, is something I meant to add as “If you like ‘According to Cain’, be sure to try Hadean Lands, though I definitely would not usually recommend it to a beginner. Not that it’s difficult, it’s just that the process of solving the game is not representative of IF in general, and as such it’s best experienced when you are already familiar with conventions. Having said that, no one’s stopping you.
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As for what is beginner-friendly… I have no idea, really, but I don’t see anything the matter with tackling a bigger game and using hints until you get used to it. I grew up with adventure games that either came with the walkthrough AND I, as a kid, thought they were like interactive movies and you were SUPPOSED to play from the walkthrough… or, in the case of the Zork collection, which had the Zorks up until Nemesis, it came with the maps and clues. And I thought you were supposed to use the maps, as opposed to mapping the game yourself. Needless to say, my playthroughs were thoroughly spoiled… and yet here I am, more than 30 years later, still in love with the genre, and very much not dependant on hints and walkthroughs.
(I’m rather sorry that I played such games as Monkey Island 1, Cruise for a Corpse, and Loom thoroughly spoiled in this manner; I feel I didn’t get to experience them properly. On the other hand, it also navigated me through some Sierra games, so I learned about Sierra’s design philosophy while at the same time learning how to play their game and maximise my chances of success. It’s a win.)
EDIT - I hesitate to recommend “A Journey Into Xanth”, but it’s fantasy and it borrows from a well-known developed fantasy world, so while simplistic it may scratch a “fantasy world” itch.