The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- Over The Top Games (Developer) (1 member)
- Overkill Software (Developer) (2 members)
- PAN Vision (Publisher) (1 member)
- PGA Tour (Series) (8 members)
- PPU LLVM Java mode handling: False (Config) (0 members)
- PPU LLVM Java mode handling: True (Config) (0 members)
- PPU LLVM accurate vector NaNs: On (Config) (1 member)
- PPU decoder: Interpreter (static) (Config) (16 members)
- PPU thread count: 1 (Config) (1 member)
- PQube (Publisher) (7 members)
- PSN status: Disconnected (Config) (1 member)
- PSN status: RPCN (Config) (6 members)
- PSN status: Simulated (Config) (2 members)
- PSR Outdoors (Developer) (2 members)
- PSR Outdoors (Publisher) (2 members)
- Pac-Man (Series) (3 members)
- PachiPara (Series) (3 members)
- Pachinko (Genre) (14 members)
- Page 44 Studios (Developer) (1 member)
- Pages using duplicate arguments in template calls (15 members)
- Pages using vgregion with named parameters (1 member)
- Pages with broken file links (1 member)
- Pages with too many expensive parser function calls (0 members)
- Pandemic Studios (Developer) (3 members)
- Paon Corporation (Developer) (1 member)
- Paon Corporation (Publisher) (1 member)
- Papaya Studio (Developer) (2 members)
- Paradigm Entertainment (Developer) (1 member)
- Paradox Interactive (Publisher) (2 members)
- Paramount Digital Entertainment (Publisher) (4 members)
- Party (Genre) (24 members)
- Patches available (273 members)
- Payday (Series) (2 members)
- Pelfast (Developer) (1 member)
- Pelfast (Publisher) (1 member)
- People Can Fly (Developer) (1 member)
- Persona (Series) (3 members)
- Phoenix Studio (Developer) (1 member)
- Pi Studios (Developer) (1 member)
- Piacci (Publisher) (1 member)
- Pieces Interactive (Developer) (2 members)
- Pinball (Genre) (7 members)
- Pipeworks Software (Developer) (6 members)
- Pipeworks Studios (Developer) (1 member)
- Piranha Bytes (Developer) (1 member)
- Piranha Games (Developer) (1 member)
- Pivotal Games (Developer) (1 member)
- PixelJunk (Series) (8 members)
- Pixel Tales (Developer) (1 member)
- Pixelnest Studio (Developer) (1 member)