NetHack 5.0 introduces over 3100 changes and fixes to this classic roguelike video game

NetHack 5.0 brings substantial changes to the roguelike’s core dungeon generation, introducing themed rooms in the Dungeons of Doom and greatly varied Gehennom levels that now include new terrain, lava, cavernous sections, and additional prefabricated areas. Special levels can now appear mirrored horizontally, vertically, or both, and the Big Room features three new layouts for further exploration diversity. Four monsters join the game, displacer beast, gold dragon, baby gold dragon, and genetic engineer, alongside new items such as two amulets, a spellbook of chain lightning, a helm of caution, and a silver mace.

Established mechanics also see changes: unicorn horns no longer restore lost attributes, amnesia no longer causes you to forget maps and object identities and instead makes you forget skill training and spells. Additionally blowing up a bag of holding will send most of its contents flying in random directions, rather than destroying them all outright, and Excalibur is harder for most roles to obtain, including Valkyries.

Alongside this content, NetHack 5.0 applies over 3100 fixes and improves accessibility throughout the interface, directly improving playability. The upgrade moves the entire codebase to C99 standard compliance, which streamlines maintenance and supports improved system compatibility. Cross-compiling is now fully supported, making it easier to build the game on one platform and run it on another.

In a shift for development, classic “yacc and lex”-based level and dungeon compilers, along with quest text file processing, are replaced with Lua text alternatives processed during gameplay. Players should note that existing saved games and bones files are incompatible with version 5.0, requiring a fresh start.