Plenty of skaters just choose the league closest to them, but there are lots of different kinds of roller derby organizations.

Derby Lite
“Roller skating for fun and fitness”

Junior Roller Derby Association (JRDA)
Kiddos. (Warning: Do not underestimate.)

Men’s Roller Derby Association (MRDA)

Modern Athletic Derby Endeavor (MADE)
Offers membership to flat track, banked track, female and co-ed leagues.

Old School Derby Association (OSDA)
“The OSDA was created for those who want to skate something more akin to what the original Roller Derby was like.” Melding of older rules with newer flat and banked track rules.

Roller Derby Coalition of Leagues (RDCL)
Banked track leagues, banded together to make a common rule set.

USA Roller Sports (USARS)
USARS manages many types of roller skating competition: speed skating, figure skating, inline hockey, and now roller derby. USARS has regional and national derby competitions, and the rules create a speedy game.

Women’s Flat Track Derby Association (WFTDA)
The largest governing body for (guess what?) women’s flat track derby.

Roller derby scrimmage in Eindhoven, The Netherlands