“Young people look at smokeless tobacco relative to cigarettes and they may say, ‘Well, this isn’t as bad as smoking’ — and sometimes that comes out as: not-as-bad-as-smoking must be harm-free, and that’s absolutely not true,” Chaffee said. “Less harmful is not harmless. There’s a perception that the risks are somewhat distant in the future and that young people feel they’ll be able to quit before those health risks come to take their toll. And before you know it, people begin using a product that is very addictive and very difficult to quit.”

The suit provides details of an athletic titan who was hopelessly addicted to dip, despite efforts to quit. He was frequently photographed with a pinch of tobacco in his cheek; his 1985 and 1989 Topps baseball cards are used in the official complaint to illustrate the plaintiffs’ argument.

In 1991, Gwynn developed swelling on the right side of his neck for a tumor that was found to be benign. The next year, he developed a lesion on his lower right lip. Fifteen years later, when his right neck swelled again, Gwynn needed surgery to remove an abscess. He soon reduced his dipping to one can per week but needed prescription drugs to manage the resulting anxiety, cravings, depression and insomnia.

Gwynn was found in 2010 to have cancer in his right parotid salivary gland. The duct from that gland, the suit says, led directly to the spot where he placed his dip for so many years. He died in Poway, Calif., on June 16, 2014 — too soon to meet his grandson and namesake, Anthony Keith Gwynn III, who was born last summer.

“People stop me in the grocery store all the time, and the first thing they ask me is if it’s O.K. if they tell me a story about my father,” Gwynn Jr. said. “I always say yes, because those type of things help you grieve. They really do. They help you get through the day.”

Gwynn said his father was proud to be a role model and would be relieved to know that his death could be a catalyst for helping to eradicate dipping.

“He wouldn’t want to see another person have to get sick and die because of what the tobacco companies did,” Gwynn Jr. said. “And in order to make that happen, these companies have to be held accountable.”