The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- AI characters (6 members)
- ARG content (7 members)
- Administration (5 members)
- Aleph One (2 members)
- Alternate weapons (2 members)
- Appearance templates (7 members)
- Articles needing an image (0 members)
- Articles needing categorization (0 members)
- Articles needing cleanup (3 members)
- Articles needing fact cleanup (0 members)
- Articles with broken file links (2 members)
- Articles with incomplete sections (2 members)
- Articles with too many About links (0 members)
- Artificial intelligence (1 member)
- Artwork (3 members)
- Astronomical objects (2 members)
- Astronomy (1 member)
- Audio files (0 members)
- Candidates for deletion (0 members)
- Character screenshots (0 members)
- Character sprites (3 members)
- Characters (3 members)
- Characters by era (2 members)
- Characters by species (3 members)
- Companies (1 member)
- Concept art (2 members)
- Cover art (1 member)
- Disambiguation (1 member)
- Documents (5 members)
- Documents by source (1 member)
- Documents by type (1 member)
- Enemies (1 member)
- Enemies by era (2 members)
- Fair use documents (7 members)
- Fair use images (12 members)
- File maintenance (4 members)
- File notices (3 members)
- File templates (3 members)
- Files needing a summary (3 members)
- Files needing categorization (0 members)
- Files to be replaced (0 members)
- Files with versions pending deletion (0 members)
- Formatting templates (14 members)
- Game concept art (1 member)
- Game covers (1 member)
- Game documents (1 member)
- Game engines (1 member)
- Game franchises (1 member)
- Game images (5 members)
- Game screenshots (4 members)
- Game series (1 member)
- Game sprites (3 members)
- Gameplay (2 members)
- Games (3 members)
- Help (4 members)
- Human (2 members)
- Human characters (2 members)
- Icons (3 members)
- Images (6 members)
- Images by Craig Mullins (1 member)
- Images by Reginald Djour (2 members)
- Images by Robert Mclees (3 members)
- Images by artist (1 member)
- Images by copyright status (1 member)
- Images by source (1 member)
- Images by subject (6 members)
- Images by type (12 members)
- Images of Pfhor characters (1 member)
- Images of characters (2 members)
- Images of human characters (1 member)
- Images of locations (1 member)
- Images of planets (2 members)
- Images of ships (2 members)
- Images of species (3 members)
- Images of technology (2 members)
- Images of vehicles (1 member)
- Images of weapons (6 members)
- Indexed pages (0 members)
- Infobox templates (9 members)
- Locations (2 members)
- Locations by era (2 members)
- Logos (3 members)
- Maintenance (8 members)
- Manual images (3 members)
- Marathon (1994) images (9 members)
- Marathon (1994) manual images (5 members)
- Marathon (1994) screenshots (2 members)
- Marathon (1994) sprites (5 members)
- Marathon (1994) terminal images (3 members)
- Marathon (202X) concept art (1 member)
- Marathon (202X) images (2 members)
- Marathon (202X) screenshots (0 members)
- Marathon (reboot) concept art (0 members)
- Marathon (reboot) images (0 members)
- Marathon (reboot) screenshots (0 members)
- Marathon 2: Durandal images (11 members)
- Marathon 2: Durandal manual images (4 members)
- Marathon 2: Durandal screenshots (2 members)
- Marathon 2: Durandal sprites (0 members)
- Marathon 2: Durandal terminal images (9 members)
- Marathon ARG (4 members)
- Marathon ARG documents (7 members)
- Marathon ARG images (2 members)
- Marathon Infinity images (4 members)
- Marathon Infinity manual images (0 members)
- Marathon Infinity screenshots (1 member)
- Marathon Infinity sprites (0 members)
- Marathon Infinity terminal images (1 member)
- Marked articles (9 members)
- Marketing documents (0 members)
- Marketing images (1 member)
- Menu screenshots (1 member)
- Menu sprites (0 members)
- Meta categories (39 members)
- Military technology (2 members)
- Navigation templates (9 members)
- New characters (0 members)
- New enemies (0 members)
- New locations (3 members)
- New species (2 members)
- New story (0 members)
- New weapons (0 members)
- Noindexed pages (0 members)
- Non-Marathon images (2 members)
- Non-Marathon screenshots (2 members)
- Notice templates (7 members)
- Organizations (2 members)
- Pages containing errors (16 members)
- Pages containing omitted template arguments (0 members)
- Pages that use a deprecated format of the chem tags (0 members)
- Pages that use a deprecated format of the math tags (0 members)
- Pages using deprecated enclose attributes (0 members)
- Pages using deprecated source tags (0 members)
- Pages using duplicate arguments in template calls (0 members)
- Pages where expansion depth is exceeded (0 members)
- Pages where node count is exceeded (0 members)
- Pages where template include size is exceeded (0 members)
- Pages where the unstrip depth limit is exceeded (0 members)
- Pages where the unstrip size limit is exceeded (0 members)
- Pages with TemplateStyles errors (0 members)
- Pages with broken file links (2 members)
- Pages with math errors (3 members)
- Pages with math render errors (0 members)
- Pages with non-numeric formatnum arguments (0 members)
- Pages with reference errors (0 members)
- Pages with script errors (0 members)
- Pages with syntax highlighting errors (2 members)
- Pages with template loops (0 members)
- Pages with too many expensive parser function calls (0 members)
- Pfhor (2 members)
- Pfhor characters (1 member)
- Planets (3 members)
- Policies (9 members)
- Raw assets (7 members)
- Real world (9 members)
- Redirect templates (1 member)
- Renders (1 member)
- Root (4 members)
- Scenarios (0 members)
- Science (1 member)
- Screenshots (3 members)
- Screenshots by subject (4 members)
- Scribunto modules with errors (0 members)
- Ships (3 members)
- Society and culture (1 member)
- Species (4 members)
- Species by era (2 members)
- Sprites (2 members)
- Sprites by subject (4 members)
- Star systems (1 member)
- Story (2 members)
- Stubs (17 members)
- Technology (4 members)
- TemplateStyles stylesheets with errors (0 members)
- Templates (25 members)
- Templates with broken file links (0 members)
- Terminal images (4 members)
- Transportation (2 members)
- Trilogy characters (8 members)
- Trilogy documents (1 member)
- Trilogy enemies (3 members)
- Trilogy games (3 members)
- Trilogy locations (4 members)
- Trilogy species (6 members)
- Trilogy story (2 members)
- Trilogy weapons (9 members)
- URL-linked files (0 members)
- URL-linked images (0 members)
- Universe and lore (7 members)
- Uploaded files (3 members)
- Utility templates (1 member)
- Vehicle screenshots (0 members)
- Vehicle sprites (0 members)
- Vehicles (2 members)
- Weapon screenshots (3 members)
- Weapon sprites (1 member)
- Weapons (2 members)
- Weapons by era (3 members)
- Website images (2 members)
- Websites (2 members)
- Wiki (10 members)
- Wiki images (2 members)