The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- Crocodile Entertainment (Developer) (1 member)
- Crocodile Entertainment (Publisher) (1 member)
- Croteam (Developer) (1 member)
- Crunching Koalas (Developer) (1 member)
- Crypton (Developer) (5 members)
- Crysis (Series) (3 members)
- Crystal Dynamics (Developer) (3 members)
- Crytek (Developer) (4 members)
- Curve Digital (Publisher) (6 members)
- Curve Studios (Developer) (4 members)
- Curve Studios (Publisher) (5 members)
- Custom servers (Netplay) (47 members)
- Cyanide Studio (Developer) (7 members)
- CyberConnect2 (Developer) (10 members)
- CyberFront (Developer) (1 member)
- CyberFront (Publisher) (8 members)
- D3 Publisher (Publisher) (27 members)
- DICE (Developer) (7 members)
- DONTNOD Entertainment (Developer) (1 member)
- DTP Entertainment (Developer) (1 member)
- DTP Entertainment (Publisher) (8 members)
- Daisenryaku (Series) (5 members)
- Dancing Dots Studio (Developer) (1 member)
- Danger Close Games (Developer) (1 member)
- Dark Energy Digital (Developer) (4 members)
- Dark Energy Digital (Publisher) (2 members)
- Darksiders (Series) (2 members)
- Date A Live (Series) (2 members)
- Day 1 Studios (Developer) (2 members)
- Dead Island (Series) (3 members)
- Dead Space (Series) (5 members)
- Deadliest Warrior (Series) (2 members)
- Deadline Games (Developer) (1 member)
- DeathSpank (Series) (3 members)
- Debug console mode: On (Config) (2 members)
- Deception (Series) (1 member)
- Deck13 Interactive (Developer) (2 members)
- Deep Silver (Publisher) (23 members)
- Def Jam (Series) (2 members)
- Default resolution: 1920x1080 (Config) (2 members)
- Default resolution: 720x576 (Config) (0 members)
- Default settings repeated (Config) (71 members)
- Degica (Publisher) (2 members)
- Demiurge Studios (Developer) (5 members)
- Dennaton Games (Developer) (2 members)
- Developers (369 members)
- Devil's Details (Developer) (2 members)
- Devil May Cry (Series) (3 members)
- Devolver Digital (Publisher) (5 members)
- Die Gute Fabrik (Developer) (1 member)