New Orleans Saints wide receiver Michael Thomas (13) scores a touchdown during the second of an NFL football game against the Los Angeles Rams in New Orleans, La. Sunday, Nov. 4, 2018.

A ballot measure that would legalize online fantasy sports games for cash prizes won approval Tuesday night in the Baton Rouge, New Orleans and Lafayette areas.

The measure is a local option in all 64 parishes, which means the games will only be legal in those parishes that endorsed them.

Voters got behind the measure in East Baton Rouge, Orleans, Jefferson, St. Charles, St. Tammany, St. Bernard and Lafayette parishes.

Others who backed it were residents of West Baton Rouge, Ascension and Livingston parishes.

Under the plan, sports enthusiasts using computers and smartphones will be able to craft teams from the NFL and other sports starting next year.

They pay an entry fee and hope to win prizes based on how those players perform in actual games.

The campaign behind the measure — $1 million — was financed by the two leaders in the sports fantasy industry: DraftKings and FanDuel.

State Rep. Kirk Talbot, R-River Ridge, sponsor of the legislation earlier this year that sparked the vote, has said the online games should be allowed because they are fun.

Ryan Berni, president and chairman of the committee behind the measure, praised the results.

"Tonight's results are a major step forward for the tens of thousands of sports fans in Louisiana who want to play fantasy sports like fans in 41 other states," Berni said in an email Tuesday night. "Adults should be able to spend their own money as they see fit, including fantasy sports, setting their own budgets and accepting responsibility for their actions, win or lose."

The chief opponents of the ballot measure were the Louisiana Family Forum, which calls itself an advocate of traditional family values, and the Louisiana Baptist Convention, which includes 1,650 churches.

Leaders of those groups contend the games would prey on youngsters, worsen Louisiana's already costly problem with troubled gamblers and legalize another form of gambling in a gambling-saturated state.

"They are being exposed to adult content in ways we never would have imagined in 1992 when the internet first started gaining popularity," said Will Hall, director of the Office of Public Policy for the Louisiana Baptist Convention.

The games are supposed to be limited to parishes that approve them using technology called geofencing, which is paid for by the fantasy sports firms.

Berni and others contend the technology is ironclad, which opponents dispute.

Legislation to regulate the games will be needed during the 2019 regular legislative session before fans can get started.

Lawmakers will hammer out rules on regulations and taxation.

Revenue gains for the state are expected to be modest.

The session begins April 8.

Follow Will Sentell on Twitter, @WillSentell.