WFTDA - Women's Flat Track Derby Association
    This is the default ruleset all others are currently based on.

MRDA - Men's Roller Derby Association
    WFTDA Rules, but with gender-neutral pronouns :-)

JRDA - Junior Roller Derby Association
    JRDA play is grouped into 3 categories by skill level.
    Level 0 - Fresh Meat - Not Bouting (No Rules)
    Level 1 - No Contact - Positional Blocking only
    Level 2 [GDocs] - Light Contact - Pushing, but no hitting
    Level 3 [PDF] - WFTDA Contact, minor changes for juniors

    JRDA vs. WFTDA Rules Matrix - A table listing the major differences between WFTDA rules and the 
                                               JRDA rules at each level. Hosted by Minor Threat Junior Roller 
                                               Derby; compiled by Sirius Hertz and Auntithesis.

Zebra Huddle - Roller Derby Officials' Forum
    Got questions? Zebra Huddle has answers!

USARS - USA Roller Sports
    The USA's Olympic Governing Body for all roller sports, including roller derby
    Rules

RDCL - Roller Derby Collation of Leagues
    Banked-Track Roller Derby governing body