"Ancient Domains of Mystery, or ADOM, is a roguelike game by Thomas Biskup first released in 1994. The player's aim is to stop the forces of Chaos that invade the world of Ancardia.
Like most roguelikes, ADOM uses ASCII graphics to represent the game world. It features a wilderness map that connects different types of dungeons. Most dungeons are randomly generated upon first enterance. Once visited, they, with the exception of the Infinite Dungeon, do not change when re-entered during play.
ADOM presents an initial choice of one (male or female) player character from ten races and twenty character classes, the combination of which strongly affects gameplay, in both subtle and obvious ways. Among other traits, character development includes experience levels, statistics, and skills. Version 1.1.0 introduced a talent system, allowing further customization of characters, based on a hierarchical system of prerequisites.
During adventures, a player is likely to explore many areas and complete multiple quests. Which quests are available may depend on character experience level or alignment (lawful, neutral, or chaotic). Alignment also affects NPC and deity interaction with the character. How one solves a quest can also affect one's alignment, such that a chaotic character seeking redemption can eventually become lawful through his or her actions (or vice versa).
ADOM offers multiple ways of winning, which vary in difficulty. The regular ending that appeared first in ADOM development, consists of locating and closing the gate through which the chaos forces infiltrate the game world Ancardia. The player also has the option to enter the gate, providing access to special endings, which are generally considered more difficult to accomplish. ADOM's quest-centric, plot-driven structure owes as much to adventure games like Zork as to the hack-and-slash of sibling games like Angband."
Source: Wikipedia, "ADOM," available under the CC-BY-SA License.