Mud pits, banana costumes, ice cream flavor identification . . . these are some of the summer’s more idiosyncratic competitive events. Most require advance registration, with prices—listed per person unless otherwise noted—increasing as race dates approach.

Urban Assault Ride In teams of two, cycling scavenger hunters head to a dozen-odd checkpoints, stopping for activities like three-legged races and riding minibikes (obstacles change each year). The event ends with a party that includes contests and free New Belgium brews for participants. Sun 5/22, 9 AM, Murphy’s Bleachers, 3655 N. Sheffield, 773-281-5356, urbanassaultride.com, $30-$60.

Chicago Beachathon This 3.45-mile obstacle course down the lakefront is billed as “the happiest race in Chicago” for obstacles like hula dancing and bingo, a costume contest, and a postrace luau. Sat 6/11, 9 AM, North Avenue Beach, 1600 N. Lake Shore, chicagobeachathon.com, $40-$60.

Bastille Day 5K Run, Walk, and Block Party A 5K run/walk culminates in a block party at the Peggy Notebaert Nature Museum with food, beer, and a cabaret. Thu 7/14, 7:30-10 PM, Lincoln Park, Cannon north of Fullerton, chicagoevents.com, $5.

Great Urban Race Teams of two complete a dozen challenges, including puzzles, scavenger hunts, and physical activities for the race’s fifth iteration in Chicago since 2007. Sat 7/23, 11 AM-5 PM, Joe’s, 940 W. Weed, 312-337-3486, greaturbanrace.com, $50-$70.

Mudathlon A muddy race with 21 obstacles like mud pits, mud slides, and giant wooden spools. A party follows with food and beer for contestants. Sat 7/23, 8 AM, Graeber Family Farms, 236 S. 200 W., Valparaiso, Indiana, mudathlon.com, $75.

Muddy Buddy For this relay race, teams of two switch off between running and mountain biking, completing obstacles at the end of each leg and finishing up by crawling together through a mud pit. Sun 7/31, 7 AM, Mini Muddy Buddy (4-13 years) at 10 AM, Indian Hills Farm, 16N503 Powers Road, Gilberts, muddy-buddy.competitor.com, $75-$85.

City Chase In this citywide scavenger hunt, teams of two compete to be the first to find and complete a series of challenges ranging from horse racing to rappelling down a building to milking a cow (those are past challenges, and they change yearly). Participants only can travel by foot or public transportation and there’s no set course for the challenge. Sat 8/27, 8 AM-6 PM, starting point TBA, citychaseusa.com, $190 per team.

City Solve Urban Race This scavenger hunt puts brains before brawn as teams of two to six people travel the city by foot and public transit, solving pop culture puzzles and math problems and taking on challenges that have included bowling a strike or identifying an ice cream flavor. The winning team gets $300 and a shot at the $5,000 prize in the national competition; teams of two aren’t eligible for prizes. Sat 9/10, noon, starting point TBA, citysolveurbanrace.com, $40-$60.