The roller derby teams Ship Wreckers and RIP Tides will compete in a furious race around the track as points are racked up. The doors open at 5 p.m. at Happy Wheels Skate Center on 3 Chabot St.

After more than a year outside the rink because of the pandemic, the Pittsburgh Roller Derby Undead team will have an intra-league bout at 5 p.m. Saturday at Neville Roller Drome on Neville Island.