The sigil-based graphics are part of what make the complexity possible. And - the dev team have coded in all manner of combinations of things, many of which get you killed in plausible/amusing/annoying/complicated ways.

There's a culture of players looking at the source code while they play. The source is really antiquated C.

If you decide to have a go, I'd recommend printing out a copy of the manual, avoiding the spoilers for the first couple of dozen games at least. Just try to learn your way around the dungeon just from that manual, and experience the complexity and sense of mystery.

It's not a particularly 'good' game - grindy. A vogue at the moment in roguelikes is for games with as little complexity as possible. For example, I've spent far more time studying the C code to this game than I have playing it: http://trogrd.tumblr.com/post/61949503427/zoo

I don't think that is relevant, I have played the GUI version for many years, and it's perfectly usable.

A letter 'c' is a cockatrice or a pyrolisk; those are both quite dangerous so I suggest you learn to recognize them for your own good.

Combat in non-enclosed spaces is hard do to ranged attacks line-of-sight, etc.

I'm slightly surprised it has taken this long to do with pudding-farming, as that lets you get plenty of really powerful items (as well as other benefits from sacrificing the corpses)[1]. There are a few parts of the game that are super hard for a bot even with the equipment of pudding farming, but I would have thought a few thousand runs would be enough to luck through them with simpler rules.

1: Puddings are creatures which can split in two when you hit them, and each new pudding will count as a corpse (which you can sacrifice to your deity for benefits) as well as having items. I don't recall all the details, but some of the rare drops from black puddings are really powerful. The idea is you take a really crummy weapon, so you don't accidentally kill the pudding and then hit it over and over again to get lots of treasure. In this run it looks like the bot used a skeleton key as a weapon.

The main deterrent for a non-bot player doing it is that it is really boring (There's a quote somewhere from the devs that is roughly "we implemented a penalty for pudding farming, it's called 'pudding farming'" Obviously the other deterrent is the prestige of beating the game without pudding farming, and that does apply to bots too.

That makes me a lot more optimistic that the bot is close to being able to ascend without farming, especially since I believe its character already had multiple amulets of life saving and a bag of holding even before starting to farm.

The essence of roguelikes is that of Diablo and other similar games: you're walking around killing things, picking up items and advancing levels. In most roguelikes, however, your freedom of movement, details of the environment, number of choices to make are on a whole another level. Why have 3 (or 5) PC classes, when you can have 20 or 22, each really unique in strengths and weaknesses, utilizing different tactics and strategies? And PC race matters too, so the number of available combinations is ~(12 times 22) before you even started playing!

One in-game example of how detailed and complex roguelikes tend to be: some levels are flooded and you can't get past water without knowing how to swim... Wait, no. You of course can go into the water, no matter the swimming skill. Without swimming skill - and with swimming not trained very high - you'll lose some HP due to drowning. You can reduce the chance of drowning by leaving your heavy equipment on the ground. On the other hand, going into the water in this shiny metal armor will make it rust. After a while. Note that there are metals that do not rust, these are safe. Also, the scrolls and magic books, if not wrapped in a waterproof blanket, become unusable after some time in the water. You also obviously don't want to try lightning based magic when standing in the water. But hey, you can just build a bridge! If you have a skill for it, a hatchet and some trees nearby. Or, and this is my favourite way, you can just freeze the water with (most of) ice based spells. But don't do this when being chased by a fire using enemy: your ice bridge can easily melt. Also, keep an eye on how much your equipment weights: bridges made of ice are not very solid. You could also get a pickaxe and try to dig your way around the water, but this takes time, so maybe a wand of digging would be better...

And that's the number of options available in only one of hundreds of different and interesting situation the game puts you in. It's an experience as close to classic table-top RPG as possible without a human as a dungeon master. It also makes you forever unimpressed with "interactive environments" and "complicated plots" of modern games.

Dwarf Fortress ruined modern gaming for me. I keep thinking "Why do they keep making new games when they could just make the old ones bigger and better?"

People love it when their games evolve over time. A new, small feature every week will keep people feeling refreshed and invested in the game.

You get potions, scrolls, weapons etc but have no clue what they are until you use them (some scrolls will help you identify what other things are in advance). Nothing about them will give you any clue (scrolls have names like "AFEWA AWEBRPO", potions are just colours etc.) To survive you need to use them though. You need to drink, but the potion might be one of weakness, poison, blindness, confusion etc. You need to eat regularly, and food is scarce, but it also might poison you. A ring of slow digestion is helpful there, but until you use an identify scroll on a ring you won't know what it is. It could end up being a ring of attract monster, for example.

Various people have used (a version of) Super Mario Bros. as a demonstration of planning AI recently. As a result, we see that people can write planning algorithms, based on imperfect information about the game state, that can complete a straightforward Mario level with some competence, but not up to the level of competence of, say, a typical '80s child.

Ascending in Nethack is an insanely difficult accomplishment that few people ever achieve. The game is much more complex than a Mario level, though perhaps the non-real-time aspect of it allows for more sophisticated planning.

The fact that someone wrote a bot to think on its feet enough to do this, is astonishing.

You should try it out in your free time, check out alt.org, there's a server where you can play and the irc channel #nethack on freenode (I believe) is very helpful and there's a few wikis available.

But beware, it becomes very addictive. The 'one more turn' rule applies heavily here.

I agree that the bot ascension is an astonishing achievement, and one I didn't expect to see for many years!

Crowning moment of awesome entry.

• Many options are available:

- Many different actions available at any given time (move, attack with a weapon, Zap using a wand, Quaff a potion, Wear a different piece of armor or equipment, Wield a different weapon, Read a scroll, Spellcasting, etc)

- Many different options available within each action (place to move, spot to place a fireball or lightning bolt, place to teleport to (!!), which piece of armor or equipment to use)

As a very rough estimate from someone who hasn't played NetHack much, I'd guess that a mid-level character might have 10^4 or so options immediately available to them at any given time, though many of these are combinatorial results of having thirty different spells that can be targeted on any of the hundred or so visible tiles. The branching factor for Chess is about 10^1.5, and Go is around 10^2.

• Options are difficult to evaluate:

- On an immediate mechanical level: If you want to use teleport, what's the best place to teleport to? If you want to cast Fireball, how do you use it as effectively as possible? If you want to shoot into a group of enemies, where do you aim?

- On a tactical level: Would this monster be more effectively dealt with by spending some energy to cast Fireball, using a charge from your Wand of Magic Missiles, or attacking it in melee and risking taking some damage?

- On a strategic level: Would it be more useful to clean out the rest of this level or immediately go down the stairs? What set of armor and weapons would result in the best chances in melee against the enemies I expect to encounter in the near future? Which of my items should I cast Polymorph on to maximize the chance of receiving a random item that would be useful to me?

- On a mathematical level, NetHack suffers significantly from the horizon problem. That is, many immediate tactical or mechanical decisions have strategic consequences that require an AI to simultaneously consider all of the above problems. You can't just have a mechanical planner, a tactical planner, and a strategic planner; you have to have a unified AI that can realize that it'd be a good idea to not kill that one enemy in the corner because it can kill it and eat it two hours later on its way back up to the surface.

This is an even nastier issue. Even humans can't do this effectively for NetHack. For example, if you look on the NetHack subreddit, one of the current top posts is "Help me make it out of this group of enemies alive!", and everybody who comments has a different idea of what the best solution is.

My neutral human wizards always have either Frostbane or Grayswandir (Magicbane as backup/for MR), robes, silver dragon scale mail, boots of speed, enchanted T-shirt, gloves of dex, etc.

Those swords barely do any more damage than Mbane even in the hands of combat classes.