Only two games have been on the hard drive of every computer I have owned since I first encountered them: Civilization, and NetHack.
Technically, NetHack is a "Rogue-like game," Rogue being the first game of this type, originally implemented for academic minicomputers before there was such a thing as a home computer. Rogue-likes are D&D-ish dungeon crawls, with randomly generated dungeon levels, and wide variety in terms of monsters, weapons, armor, spells, and magic items. Rogue wasn't a bad game--but there's nothing like NetHack.
It's "Net" not in the sense that it's multiplayer, but in the sense that it's developed and maintained by an open-source development team collaborating over the Internet. And indeed, the NetHack dev team was iteratively improving the game long before rms coined the term "free software" or esr came up with "open source." (esr was a NetHack dev team member for a while, btw).
Playing NetHack reminds you of how bogus the modern game industry is--because a pure ASCII title delivers vastly more gameplay, and more fun, than 99% of the crap you'll find on the shelves at GameStop. Gameplay over glitz.
Playing NetHack can be frustrating; although there are occasional hand-crafted levels, mostly are randomly generated, and you can easily be screwed by bad luck. But it's quick to play, and deep, and will keep you occupied for... well, years, potentially. If hack-and-slash dungeon crawling sounds like fun, you're an idiot if you don't download this game. It's free, after all.
Hints
When your character dies, NetHack erases its last save file. So when you save, navigate to the directory where you saved it, copy it someplace else, and when you die, recopy to the Nethack directory and reload. This is "cheating" in some abstract sense, but actually, NetHack notices that you've done this (with occasional gentle chiding), but doesn't stop you.
If you get deep into the game, you will absolutely want the NetHack spoilers. We won't link from here, but do a Google search.
And... if you really want to beat the game, and know C, consider reading the source.
One of the greatest games of
One of the greatest games of all time. A perfect example of depth over breadth.
If you like NetHack....
I personally prefer ADOM. ADOM sticks to hardcore geeky roguelike purity with the mindboggling attention to detail, ASCII graphics, and brutal perma-death. But it has a better interface, no silly jokes and it is, oh yeah, fun.
If you call yourself gamer though, I mean a real gamer, you have to be able to say you play at least one of these classics. I run ADOM right off my USB memory stick, so I never leave home without it :)
I'm goin for it...
A free ASCII dungeon crawler where the advice to beat the game involves accessing the source code!? Where do I sign?
Thanks for the post.
btw - since this is my first comment let me congratulate you on a truly amazing site. Thanks!
The game deletes saves for a reason
Sorry, but I must disagree with 'hints' stated here. I think they're harmful for the player.
I understand I may sound too much like a 'hardcore roguelike player', but permadeath is considered the most important aspect of Nethack. There are numerous reasons for why starting the game with save-scumming, as you recommend, isn't going to do it much justice.
Simply put, games like this are not only about the character advancing - the player also gains experience. If you just ignore the cause of your death, simply reload and play that again and again, you will get bored quickly and dismiss the game as badly designed and impossible to beat. Paradoxically, replaying for the start will be more interesting, as the game generates different levels and items every time, so everything can happen.
And, of course, you don't have any bragging rights if you win, as you haven't beat the game by its rules :)
Similar thing can also be said about spoilers (this, however, is. One could say the whole fun of Nethack lies in discovering everything by yourself - and even if spoiling yourself is unavoidable (it's a hard game after all), the later you do it, the better.