"See yonder, lo, the Galaxyë
Which men clepeth the Milky Wey,
For hit is whyt."
—Geoffrey Chaucer, The House of Fame, c. 1380.
By far the most famous or familiar galaxy is our own Milky Way, so named because it appears from earth as a band of whitish material in the sky, as though someone had splashed milk upon the heavens. Of course, in actuality, it's all around us, but from our vantage point the majority of the stars appear to be in a narrow band of the sky, sort of like a celestial 'horizon'.
The milky way includes the Earth and the Sun, as well as the rest of the Solar System. It also includes over 200 billion additional stars (and all the planets, etc, that orbit them). The milky way is a four-limbed spiral 100,000 light-years long, and 3,000 light-years tall at it's widest part, making it average to a little larger than the average "large galaxy". Our solar system is located inside several interestingly-named portions of the Milky Way, such as the Orion Arm, the Local Fluff and the Local Bubble. At the heart of the milky way is a supermassive black hole known as Sagittarius A*.
Game and Story Use
- The default setting of near-future, or historical games. The Milky Way is roughly typical for large galaxies of it's type, so even if your game is technically set in some other reality, it's likely to be in a place more or less a lot like the Milky Way. Go with what you know!
- The billion-year-long merging process as our galaxy collides with the Andromeda galaxy, would make for an interesting setting. It's billions of years from now, so if humans are still around there'll either be sufficiently advanced technology or a post-apocalyptic dark age. The actual stars are unlikely to strike each other because there's so much space between them, but rogue planets will abound and many system's usually gravity and orbits may be disrupted. It's an incredibly slow process, so not really the sort of thing you put front and center as your main natural disaster plotline. But if you think of those rogue planetoids as dungeons or ruins full of ancient technology waiting to be explored, packed with monsters from either of two galaxies, you've got the makings for an exciting adventure game. Strong dualism or differentiation between worlds from each of the two galaxies could be a neat theme.
- Games with strong mythological and/or magical component can veer vastly away from what the Milky Way is really like. In many ancient belief systems, the Gods are (or are associated with) various planets and stars. The Milky Way could be some great palace they've constructed, or the Celestial Chorus, or just the heavenly representation of all the minor godlings and spirit-beings of the pantheon (or monster manual).
- Sagittarius A* and the Galactic Center? It's really Azathoth. Astronauts beware.