alt Hacker NewsI agree Nethack is not one of those games. People always pretended it was, though. They called "spoilers" what would be called documentation in most games. No one didn't use them (the "unspoiled" win mentioned elsewhere in the thread was a stretch even if you take them at their word). It was supposed to be theoretically possible to find out core game features from e.g. random rumors, but that was completely hypothetical - I'm pretty sure at no point in Nethack's development was it ever playtested with new players.
Not just random rumours, there are multiple specific mechanisms built into the game that explain core features, which a curious player can stumble on and then deliberately mine for information.
NetHack in many ways has common heritage with text-based adventure games of the 1970s and 80s, such as Zork. NetHack’s in-game currency is even a reference to Zork! Solving Zork without spoilers is also extremely difficult, despite lacking the tactical combat of NetHack. However, playing Zork with spoilers completely ruins the game, whereas NetHack is still a lot of fun even for highly spoiled players.