Oathbreaker draws ideas and inspiration from a wide selection of roguelikes.
Boohu and Harmonist:
- Upgrades (i.e. "talents" or "abilities") that are awarded on reaching a new level (Boohu).
- Simplified inventory management (i.e. only holding one armor/weapon/cloak at a time).
- Windows! (Harmonist)
- Lack of traditional regeneration (TGGW, Boohu, Harmonist, Cogmind)
- Drains (Harmonists' barrel stones)
- Terrain-based positioning (with fungi, metal and wood floors, etc) was an original idea, but was influenced by Boohu, TGGW, and Brogue.
- Positioning-based confusion effects (Boohu).
The Ground Gives Way:
- Many details of the stats and resistances system, which in turn was inspired by POWDER.
- Many of the combat animations (such as knockback, blocked attack, and damage).
- Lack of traditional regeneration (TGGW, Boohu, Harmonist, Cogmind)
- Terrain-based positioning (with fungi, metal and wood floors, etc) was an original idea, but was influenced by Boohu, TGGW, and Brogue.
- Treasure vaults (TGGW's Stone and Golden rooms).
- The Spikes stat.
- Many other items were indirectly inspired by items in TGGW.
Brogue:
- Gas traps (and the gas mechanics in general).
- Terrain-based positioning (with fungi, metal and wood floors, etc) was an original idea, but was influenced by Boohu, TGGW, and Brogue.
Cogmind:
- Explosions and destructible terrain in general.
- The one-item-per-tile rule.
Other:
- The lighting system was inspired by Golden Krone Hotel 7DRL.
- Many monsters and their abilities were inspired by DCSS, such as ether fiends (servant of whispers), ancient magi (liches), wardens (vault sentinels), dustlings (saltlings), death magi (death knights... sort of), bone magi (moths of wrath), etc.
- And of course, monster cone-shaped LOS and pattern-based abilities was stolen directly from Ironwood.
The following resources were also immensely useful while developing Oathbreaker:
- Many mechanics in Nethack were good case studies of what constitutes bad roguelike design.
- The prefab system was taken from Golden Krone Hotel's dev blog.
- The place-random-rooms map generation algorithm, used for Prison and Laboratory, was taken from here
- r/roguelikedev's FAQ Friday and Sharing Saturday events were immensely helpful.
- GridSageGames' dev blog was a valuable resource as well on game design and balancing.