Dress in your Mardi Gras best for music, casino games, food, silent and live auctions, bingo and drinks for Opportunity Builders’ 15th annual Mardi Gras Fundraiser, which has raised nearly a quarter of a million dollars in 15 years to train adults with developmental disabilities. 6-10pm at 8855 Veterans Hgwy., Millersville. $65 w/rsvp discounts; sponsors $50-$5,000: 410-787-0700; www.obiworks.org.