All the text games come with maps. But the manual says we need to DRAW A MAP during gameplay, suggesting that it is part of the challenge. So if we look at the maps, are we in fact looking at SPOILERS?

If you're referring to the Invisiclues Maps that come with the anthology, then (after a glance at them) yes I'd classify them as spoilers as they're complete maps taken from the hint books.

Sometimes Infocom text adventures would also come with maps of mazes as part of their feelies, Leather Goddess of Phobos being the one that jumps to mind, which would double up as a form of copy protection as the mazes would be otherwise all but impossible to get through. While theres a couple of 'Feelies' maps in the anthology, the vast majority look like spoilers and none of the copy protection variant.

I'm fine with drawing a map in general, but at least the first Zork game doesn't seem to play fair regarding the directions it gives, which makes drawing a map not only part of the challenge but almost the greatest challenge of it all.

How do you draw a map, when e.g. going EAST and then back WEST makes you arrive at a different location than where you started from? When you e.g. go NORTHEAST then have to travel WEST (not SOUTHWEST) to get back there? When SOUTHEAST is suddenly the same as UP, but you can only go back DOWN and not NORTHWEST? etc. (And I'm not talking about teleporters or mazes, just regular confusing inaccuracy with the directions.)

Is this common in the other Infocom games, too? How do you deal with it?

I sure hope it's not, although I might just play with the cheat-map opened to focus on the puzzles, not on finding my way around.

If it looks like a flowchart, it's a spoiler map. Part of the game is/was supposed to be getting sheets of paper out and drawing your own, or getting a mental map in your head. Typically you don't really need to-- it's the Zork and Enchanter games that you'll really need maps for, for the most part.

Think of it as drawing a circuit diagram, if that makes sense. Give each box plenty of room on the page, and don't be afraid to make your path lines bend from the south side of one box to the north-east corner of another, or hop over one another. The Implementors didn't.