Like rappers, roller-derby girls benefit from an intimidating attitude and the skills to come up with a unique yet menacing new moniker without consulting online name generators. Admire new nomenclature with today's Groupon: for $21, you get two tickets to see the Rose City Rollers play against Seattle's Rat City Rollergirls on April 23 at 5:45 p.m. at the Memorial Coliseum (a $43.50 value including fees).

The Rose City Rollers, an all-female, flat-track roller-derby league, represent Portland with their grit, determination, and hard-hitting elbows. In their second matchup of the season, the Rose City Rollers go nose to elbow with the Rat City Rollergirls for four 30-minute skate-stomping, incisor-loosening bouts. Four-wheel disciples shake the walls of the 12,000-capacity Memorial Coliseum as they clamor for the home teams: the Break Neck Betties, the Guns N Rollers, the High Rollers, and the Heartless Heathers. Like football on wheels or a turf war on skates, these ferocious femmes use their concrete-inspired blocking skills to get the team's lead jammer from the back to the front of the pack, evading elbow thrusts, hip checks, and blanket-heavy clotheslines. Doors open at 5 p.m., giving the crowd enough time to practice their cheers and jeers.