Allies of former President Donald J. Trump charged in a sweeping Arizona election case on Friday began filing what is expected to be a series of challenges, seizing on a new state law aimed at curbing litigation and prosecutions involving political figures.

The law was originally crafted by Kory Langhofer, a Phoenix lawyer who worked for the Trump campaign during the 2020 election but who subsequently fell out of favor with the former president. He said the 2022 law’s intent was to limit politically motivated prosecutions on both sides of the aisle.

The new challenges could have the effect of delaying the election case in Arizona for several months, given the timeline for decisions and appeals. The case was brought in April by the state attorney general, Kris Mayes, a Democrat.

The 18 defendants have each been charged with nine counts of fraud, forgery and conspiracy. The indictment lays out a series of efforts by the defendants to overturn Arizona’s election results, from the plan to deploy fake electors on Mr. Trump’s behalf, despite his loss at the polls, to the steps some took to put pressure on “officials responsible for certifying election results.”

Seven Trump advisers are among those charged, among them Rudolph W. Giuliani, Mr. Trump’s former personal lawyer, and Mark Meadows, the former White House chief of staff. Eleven Republicans committed to Mr. Trump who claimed to be the state’s electors, even though President Biden had already been certified by state officials as the winner in Arizona, were also charged.