Role-playing Games
Q&A for gamemasters and players of tabletop, paper-and-pencil role-playing games
Bicycles
Q&A for people who build and repair bicycles, people who train cycling, or commute on bicycles
Code Review
Q&A for peer programmer code reviews
Stack Overflow
Q&A for professional and enthusiast programmers
English Language Learners
Q&A for speakers of other languages learning English
Puzzling
Q&A for those who create, solve, and study puzzles
Worldbuilding
Q&A for writers/artists using science, geography and culture to construct imaginary worlds and settings
Electrical Engineering
Q&A for electronics and electrical engineering professionals, students, and enthusiasts
Science Fiction & Fantasy
Q&A for science fiction and fantasy enthusiasts
Law
Q&A for legal professionals, students, and others with experience or interest in law
English Language & Usage
Q&A for linguists, etymologists, and serious English language enthusiasts
Meta Stack Exchange
Q&A for meta-discussion of the Stack Exchange family of Q&A websites
Game Development
Q&A for professional and independent game developers
Arqade
Q&A for passionate videogamers on all platforms
Physics
Q&A for active researchers, academics and students of physics
Engineering
Q&A for professionals and students of engineering
Artificial Intelligence
Q&A for people interested in conceptual questions about life and challenges in a world where "cognitive" functions can be mimicked in purely digital environment
Hardware Recommendations
Q&A for people seeking specific hardware recommendations