The lawsuit says CenturyLink Arena, home of the Idaho Steelheads hockey team, defrauded customers by charging $3 more for a tall, narrow cup advertised as a "large" that actually holds the same amount of beer as the shorter, wider cup described as a "small."
Arena spokesman Mike Campbell said he hadn't yet seen the lawsuit and can't comment.
Four fans filed the suit Tuesday in Boise's 4th District Court against Block 22 LLC, which does business as CenturyLink Arena. Brady Peck, Michele Bonds and William and Brittany Graham are seeking $10,000 in damages.
In the lawsuit, Peck says he's attended at least 30 events over the past three years at the arena, including a hockey game on March 5, and that he's purchased beer each time. The other three plaintiffs say they have been attending sporting events at the venue for five years and that they bought at least one large $7 beer at each event.
"While different shapes, both cup sizes hold substantially the same amount of liquid and are not large versus small in actual capacity," the group's attorney, Wyatt Johnson, wrote in the lawsuit. "Defendants knowingly sold each of their beers in a similar manner at each event held at the arena where beer was sold for at least the last five years."
The lawsuit came just two days after another hockey fan posted a video on YouTube of what the fan said was a beer purchased at CenturyLink Arena on March 8. That video shows a patron holding a large cup of beer and pouring it into an empty small cup. In both cups, the beer reaches nearly to the brim.
Gwen Gibbs, who posted the video, told the Idaho Statesman that she was annoyed when she saw her boyfriend, Heath Forsey, pour the large beer into the smaller cup and so decided to upload the video. CenturyLink officials announced a short time later that the company would purchase new cups for the large beers that would hold 24 ounces instead of the previous 20 ounces for a bigger difference in size.
At the time, Eric Trapp, the president of the Idaho Steelheads hockey team and CenturyLink Arena, wrote on the team's Facebook page that the company had ordered 16-ounce and 20-ounce cups and never intended to mislead customers.
"It's amazing what can be done with one little video and the power of social media," Gibbs told the newspaper, joking that she hoped CenturyLink would rename the 24-ounce cups the "Heath and Gwen size."
CenturyLink Arena hosts concerts and other events and is also home to the Idaho Stampede, an NBA development league.