Former Vice President Joe Biden's political action committee is using a trip contest to encourage small dollar contributions from individual donors.

Biden's American Possibilities PAC is asking for donations of as little as $5 in return for the chance to win a $3,500 trip to meet him. It comes as Biden travels around the country to support Democratic candidates in the upcoming midterm elections.

"We'll fly you out, and put you up," said email online solicitation from the PAC. It offers "the opportunity for winner and winner's guest to meet Vice President Joe Biden on the campaign trail."

Biden is scheduled to campaign Sunday in Rhode Island with fellow Democrats, including Gov. Gina Raimondo who is running for reelection as well as Sen. Sheldon Whitehouse, D-R.I., in his bid for a third term.

The former vice president also is scheduled to headline a political fundraiser on Oct. 3 in Beverly Hills, Calif., to raise money for his PAC focused on electing Democratic candidates. It comes as Biden himself is considering a 2020 presidential run.

"From time to time, candidates and others have tried to come up with new gimmicks and novel ways to raise campaign contributions," said Lawrence J. Tabas, chair of the election law practice group at the law firm Obermayer Rebmann Maxwell & Hippel in Philadelphia.

Tabas added, "Once you get outside of the large donor base, raising small dollar amount contributions can be very difficult. While direct mail and email solicitations for small contributions can be modestly productive, a raffle or lottery with a small ticket price, such as the one for $5, may potentially generate significant funds if the prize is worth it."

Regardless, the attorney said there are "strict rules" in many states that candidates or political committees must follow for these kind of fundraising contests and indicated they are essentially "a game or chance." There also have been instances of campaign contests getting challenged in some states.

That said, Tabas indicated federal campaign finance laws do allow PACs to sometimes use raffle contests for fundraising.

Fundraising contests can also become "an administrative nightmare for the Vice President's committee to ensure legal compliance," said Tabas, who has served on the legal teams of various GOP political campaigns over the years, including presidential campaigns.

"American Possibilities consulted with counsel to develop and publish detailed rules and disclaimers, to ensure compliance with any applicable laws," Bill Russo, a spokesman for Biden, told CNBC in an email. "They made explicit in the rules and other promotional materials that no contribution is necessary to enter or win, and the rules make clear that the promotion is void where prohibited."

According to the contest, the winner and guest will receive coach-class airplane tickets to a campaign stop as well as ground transportation to and from the destination. There's also an overnight hotel stay included as part of the "prize package," which the contest valued at $3,500.

The winner is responsible for paying any taxes associated with the prize, according to the contest rules. It said the "odds of winning a prize depend on the number and quality of eligible entries received," which it estimated at about 10,000 total entries.

The PAC's website added that "no purchase, payment, or contribution is necessary to enter or win and will not improve chances of winning."

-Adds comment from spokesman for former Vice President Joe Biden and clarifies the campaign schedule.