Totally Underappreciated
I first heard about this game from one of my friend's dads in middleschool. He simply said, "well it's a dungeon crawler where if you die, you lose your save and start again." I thought it'd be worth a shot. Little did I know I was stepping through a portal into another supremely developed, difficult game that would eat my free time for the next 8 years. The basic premise makes it sound very simple, you enter the dungeons to get the Amulet of Yendor from the similarly name Wizard, and bring it back to your deity and #offer it to them to effectively "ascend," and win the game. However, once you actually get into it, you'll find one of the most complex and intricate design systems I've ever seen. For example, an intricate stat exercising system is in place to improve you character's stats every 600-1500 turns. Each stat has a range of options on how to excersize or abuse them. If you've sufficiently fulfilled a set requirement one way or the other, you will gain/lose a stat point. Also, when you begin the game not all objects will be identified to you, and so you must figure things out on your own; such as, if you drop an unidentified ring down a sink drain, you will get a specialized message for each type of ring in the game, and are then prompted to identify it. As it has been said, the DevTeam thinks of Everything.
There are thirteen starting roles to choose from, all fairly standard RPG characters ranging from archeologist to wizard. Each begins with their own somewhat randomized set of inventory, providing even more unpredictability to the game. The early game is typically easy, although some random monster spawns might get you into a bit of a jam, for example if you quaff from a fountain and accidentally summon a water demon, that's typically ground for an instadeath to low level characters. Caution and planning for each character are essential to survival in the dungeons, you must have a strict plan of how to tackle each set of levels and follow it, giving some leway due heavy reliance on an RNG.
Almost every dungeon level is randomized, with certain exceptions, such as the downstairs to the Gnomish Mines is always on somewhere between level 2-4. Furthermore, certain special levels e.g. the Castle level are never randomly generated. In a game than can get extremely hectic, these beacons are like a beacon of hope, a piece of sanity in an otherwise completely insane world.
In short, this freeware RPG is easily the most necessary game for ANY gamer to play, I mean it's free, WHY WOULDN'T YOU?!