NEW YORK – Activision Blizzard, the world’s largest video game publisher, turned the war-oriented series “Call of Duty” into a $3 billion franchise in the past six years, a best-seller with more than 55 million units sold.

Chief Executive Officer Robert Kotick decided to put some of the profits into helping real war veterans find work. Last year he started the Call of Duty Endowment, a non-profit that makes grants to charities that aid veterans.

Kotick, who started his first software company as a 19-year-old University of Michigan student and is now 46, said he plans to boost the non-profit’s endowment to between $50 million and $100 million by the end of the decade from about $1 million today.

“When you think about the people coming back from the Middle East and Afghanistan in the next five years, that could be as many as 50,000 people,” Kotick said in a phone interview from his Santa Monica, Calif., office.

Two years ago, Kotick approached Jim Nicholson, then secretary of the Department of Veterans Affairs, with a proposal to fund a park in Los Angeles for military veterans.

“Jim said, ‘Do you think veterans give a ---- about a park?’ ” Kotick said. “ ‘Do you know that the unemployment rate for veterans is three times the national average,’ and then he went on about the challenges. Veterans’ unemployment really stuck in my mind.”

The Call of Duty Endowment, or CODE, made its first grant, of $375,000, in November to the Washington, D.C.-based Paralyzed Veterans of America to set up a vocational center in Boston.

This month, CODE will make a $100,000 gift to the Wounded Warrior Project, a Jacksonville, Fla.-based charity that helps injured war veterans make the transition to civilian life or new military jobs. The money will be used to open up its fourth training academy and track the veterans’ progress.

“We wanted a program that did more than just get wounded soldiers out of their rooms,” said Chris Roberts, manager of Wounded Warrior’s transition-training academy.

Fueling the CODE philanthropy is Activision’s publishing of “Call of Duty,” created by Infinity Ward of Encino, Calif. The most recent version of the game, “Call of Duty: Modern Warfare 2,” has surpassed $1 billion in sales.

Kotick serves as a trustee for the Los Angeles County Museum of Art, the West Hollywood, Calif.-based Center for Early Education and the Tony Hawk Foundation, set up by the professional skateboarder to fund and promote the establishment of skateboard parks in low-income communities.

Kotick has developed friendships with U.S. war veterans. He is taking helicopter piloting lessons, has visited servicemen posted on U.S. Navy carriers and gives some of them advice on how to pursue a career in business when they leave the military.

“Being able to meet these brave men and women and hear their stories firsthand has strengthened my conviction that the private sector as well as the government is responsible for ensuring they have employment and that we don’t penalize them for their years of service to this country,” he said.