Roguelikes are descendants of the game Rogue which feature procedurally generated dungeons consisting of rooms interlinked by tunnels. In Hack, NetHack and the majority of other roguelikes each dungeon level consists of a single screen with stairs linking dungeon levels and dungeon levels are persistent. In Moria, Angband and the large number of Angband variants the dungeon level spans multiple screens and dungeon levels are non-persistent.
Roguelikes usually feature permadeath, which means that the game must be completely restarted after the character dies, as opposed to having a saved game that they can recover to. The procedural generation of dungeon levels allows the player to have a new game experience every time they play.
Some roguelikes also feature randomized item types, which requires that the player learn or identify through magical means the abilities of the items. The randomization of these items is usually done through a template of a standard version of the item plus a random factor plus or minus to various abilities. Random artifacts in some Angband variants are generated in a more complex fashion, with the random artifacts attempting to match a particular power level, including an assessment of monster power levels in the dungeon to determine the effectiveness of a particular item ability.