ADOM

ADOM (short for Ancient Domains of Mystery) is a roguelike game in which your aim is to stop the forces of Chaos which are invading the world of Ancardia. Like most roguelike games, ADOM uses ASCII graphics to represent the game world.

The player can create their character as male or female, any of ten races and any of twenty character classes, giving 400 possible combinations requiring widely varying playing styles.

For example, a High Elven Wizard would annihilate their enemies by slinging spells at them from afar, while a Trollish Barbarian would have great difficulty learning spells and would be better off smashing everything in melee combat.
During adventures, a player is likely to explore many different dungeons and complete multiple quests. Which quests the player chooses will likely depend on their character and on whether they are lawful or chaotic. The alignment of a player also effects which benefits (or curses) their god may bestow upon them, and how they are treated by NPCs. ADOM has a quest-centric, plot driven structure that borrows as much to old adventure games such as Zork (indeed, there are even Grue references to be found) as it does to the "purer" hack-and-slash of sister games such as Angband.

ADOM was written by Thomas Biskup, is currently at version 1.1.1 and can be downloaded from the official site. Although ADOM is freeware (technically postcardware), unlike most roguelikes, its source code is not available. However, some of the game's underlying equations and mechanics have been deduced via careful experimentation by players.

Biskup did not release the source because: