NetHack becomes bland if you're too good at it.

NetHack is a challenging and intricate game! But to me, it loses its lustre about halfway through a game of it.

Whenever I get a decent game of NetHack going, I start rapidly losing interest when I reach the second half of the game.

Ok. So let's try and describe NetHack and its structure.

NetHack is basically a hugely expanded-upon Rogue...though that's putting it simply.
Rogue is the pioneer and namesake of the 'roguelike' genre of games.

Briefly described, a roguelike is a game that takes place in a randomly-generated world.
Generally, if you die in a roguelike, the game is over and you must start a new character in a new world from the beginning (though NetHack does have a friendly "exploration" mode where you can choose to not die).

Some examples of modern (and currently popular) roguelikes are Spelunky and The Binding of Isaac.
Roguelikes typically require the player to have a lot of knowledge about interacting elements in order to do well. Though death is typically permanent, every in-game death is a new learning experience, and the gratification of roguelikes comes from using your knowledge to constantly avoid death, and using the resources at your disposal to try to get yourself into an advantageous state.

NetHack is one of the oldest and most well-known and well-regarded roguelikes around. The first version was released in 1987, and crazily enough, it's still in development - though for the longest time we weren't so sure about that.

I personally got into NetHack in 2006, while it was in version 3.4.3, which was itself released in December 2003.
The next release of the game, version 3.6.0, didn't come until December 2015! We had all given up on there ever being a new version for the longest time. It's somewhat remarkable for a game this old to still be in active developmemt ... though to be honest, the new version didn't really fix any of the major outstanding problems I had with the game.

So, anyway, what's the game like?


Well, it runs entirely in the command line interface, and is completely text-only.
Back in the day, this was because computers didn't even have graphics. Most computer games were text adventures like Colossal Cave Adventure (also known as just 'Adventure'), where the player had to type in commands and received lines of text back.
It's interesting how a more graphical representation of a game world was considered quite novel back then, but has now become the overwhelming norm.

The game uses the text characters to represent various dungeony things. Letters are monsters, punctuation marks are items, and various lines and dots make up the overhead-view of walls and corridors of the dungeons.

There are options to use special characters for a smoother look (as seen in my screenshots), and in the modern incarnations, there is indeed a way of displaying the game with graphical tiles instead of ASCII. But I actually much prefer the ASCII look - the tile view looks kind of messy and cheapo to me...the ASCII look is 'classier' in its own way.

 A scene in the normal command-line view.

 The same scene in the graphical tiles view.  I personally think it looks kinda bad like this!

Plus, knowledge of which character represents what things can actually be beneficial to the game in important ways. (Take my word for it, there are situations where it's extremely useful to know every kind of monster that can be represented by a lowercase 'h', for example)

The game is heavily inspired by Dungeons and Dragons. You wander around a dungeon in a top-down view, fighting monsters and grabbing cool loot. The various monsters and artifacts are taken from all sorts of mythology and fantasy stories, including a lot from D&D, a lot of Tolkien, and a bit of Pratchett as well.

I personally really like this kind of 'anything goes' mishmash fantasy setting. (It's why I love Castlevania, too!)

The game is turn-based. If you leave it alone, nothing happens until you input your next command. This gives you a lot of time to think about the situation your character is in, and allows you to plan the best course of action.

The game is controlled entirely with the keyboard - you use the numpad to move in eight directions, and each letter key corresponds to a possible action. For example, 'e' is 'eat' and 't' is 'throw'. There are too many commands for the amount of keys on a keyboard, though, so they had to use Shift and Ctrl to make more available: Shift+T is 'take off' (remove armor), and ctrl+t is 'teleport' (which only works if you have the ability, naturally). They had to get creative with some of them, too - the command for "drink" is 'q', which supposedly stands for 'quaff'. ...I guess 'd' was already taken for 'drop'.

The player descends the dungeon one floor at a time. Each floor has a ladder down, and a ladder back up, and when you leave a floor, everything stays exactly as you left it until you come back. The overall goal of the game is to reach the bottom floor, grab the Amulet of Yendor, and then get all the way back to the top. If you can do this without dying, you win!

Exploring! Killing monsters! Finding cool loot!

One important factor about this game is that different magical objects have randomly-assigned appearances that change from game to game. An item described as a "milky potion" may be a Potion of Healing in one playthrough, but a Potion of Sickness in another! This is one of the most important aspects of the game - the need to identify found objects, either by testing them safely, or by reading a Scroll of Identify. Once an item is identified, your character will remember it, so you don't have to keep track yourself.

One important thing to note is that it is extremely easy to die in NetHack.

Generally, you die by losing all your HP. (but there are also ways to die instantly)
Often you die because you don't know what's going on, or you don't know how a particular item or enemy behaves. A new player may decide to drink an unidentified potion, or to try to eat rotten food, or to fight a monster that is too strong, or whatever else, and they will die from all sorts of actions that an experienced player would just not try to do.

Staying alive in this game requires a ton of knowledge about the inner workings of the game. You need to know about how to gain various intrinsic resistances (Fire resistance, Poison resistance, etc). The need to acquire certain items or tools that will be useful in particular spots. (quick example: A mirror is useful for dealing with Medusa). The knowledge of which things are safe to eat (it's a bad idea to eat the violet fungus), which monsters are safe to engage in combat (don't touch Floating Eyes!), which useful resources are likely to appear in certain spots (Armour shops can be more useful than you'd think), and all sorts of other tiny pieces of information that could very well mean the difference between life and death.

I am someone who has a pretty good understanding of everything NetHack is capable of throwing at me. During my initial obsession in 2006, I poured over the wikis and knowledge bases, trying to learn everything I could about the game. I played on the public NetHack server at http://alt.org and participated in the IRC chat community to learn more about the game and share ideas and advice. It was pretty fun, I stayed up quite late on many occasions. I played many games, dying again and again and again, learning through each playthrough. I even won a few games without dying, which was pretty exciting, and is by no means a small feat.

But there comes a point where the game starts to fall apart.

So, okay. If I've won a few times, why would I want to keep playing new games of NetHack? Well, it's randomly-generated, so you'll never get the same layout twice. It's always a new adventure, even if it always does take place within the same set of rules and systems.
The answer is that I've spent a lot of time and effort acquiring almost comprehensive knowledge about this one game's systems and mechanics, and I find it quite fun and mentally challenging to put my knowledge to good use. I can be assured that if I die, it won't feel unfair like it was the first several who-knows-how-many times, since I will feel like I should have been able to come up with a way to survive using my knowledge of the game.

But with this knowledge comes somewhat of a reduced sense of intrigue. Once you know everything in the game, there's not much mystery left. Once you know the best course of action, there's not much experimenting left. A new player who luckily stumbled upon a djinni who grants their wish may wish for something that they may be aware exists in the game: "I want a Ring of Fire Resistance!", yet an experienced player pretty much knows that the best item from a lucky early wish is usually a "blessed greased +2 grey dragon scale mail".
The savvy player knows the important items generally needed throughout the game - A Bag of Holding, a Ring of Levitation, a unicorn horn, etc., and so the player will plan and adjust their route throughout the game with the goal of making finding this stuff more likely.

The dungeon is approximately 50 floors deep. At around floor 25, there is a special level that is always the same known as the Castle. The Castle is the dividing line at which the game stops being interesting.

It's the Castle. If you stop playing when you reach here, I won't blame you.

Levels before the Castle are known as "The Dungeons of Doom", and levels after the Castle are called "Gehennom". (ignoring the level branches, for the sake of simplicity).
Dungeons of Doom levels have a simple yet effective "room and corridor" structure, where rectangular rooms are connected via narrow corridors. Some rooms are hidden, some have cool items, some rooms can randomly be shops, or have other interesting things going on: throne rooms, treasure rooms, secret vaults, monster nests... etc etc. This is the early game, where the player is still trying to get equipped. Any treasure you find at this point is exciting. Shops can have interesting items that you may have to remember to come back for later. Unidentified magical items are brimming with the potential to be good stuff. It's fun to pick things up and explore around, because anything you find could turn out quite useful for something later on.

Levels in Gehennom, however, are BORING AS HELL. Gehennom doesn't have specific rooms, and instead turns every dungeon level into an annoying maze. 

 The mazes here get really cumbersome

It's not too difficult to find the way down, but it's just annoying. There's still a large number of items strewn around Gehennom, but by this point, you've likely got everything you really need and are probably carrying too much junk around anyway, so you generally don't care about getting more items. The toughest and most annoying monsters live down here, meaning you have to constantly be on edge and alert. Unlike the Dungeons of Doom, where you can take things one room at a time, the mazes of Gehennom are just a constant draining slog of having to pay attention at all times as you find the staircase down, and then carefully creating a path from one staircase to the next in preparation for your eventual climb back up.

Sometimes when I reach this point, I think to myself.... ehh. I don't feel like grabbing the Amulet of Yendor today. I think I'll just start a new game from the beginning, find a cool ring, and then die to a newt or something. That sounds like more fun than going through Gehennom and winning.

It's a bit of a shame really. I really do like this game, but it just...gets boring and samey when you reach the endgame.

Maybe that's just me though. I will say that sometimes it doesn't feel like that at all - there are times I enjoy the endgame. But more often than not, I just lose momentum and stop playing.

Oh well