If you're not familiar with steampunk, it's a subgenre of sci-fi [1] that reimagines modern technology in a Victorian historical setting. Think goggles, lots of brass, advanced monocles, and clothing from the 1800s. Machinery is steam-powered, and the style is very distinct and wildly badass. Because there are so many fun ways to play up steampunk, it makes for the perfect Halloween [2] costume. See 24 awesome ideas ahead that will blow you away.
