Anti-discrimination legislation approved by the New York Legislature in June will increase employers’ potential liability, say observers.

Some experts believe the omnibus bill approved by the New York state Senate and Assembly, which expands statewide laws already in place in New York City as well as 2018 state legislation, will be influential in other states.

A spokesman for the office of New York Gov. Andrew Cuomo said the legislation will be reviewed, although observers say he is expected to sign it.

Key provisions of the legislation include expanding the definition of unlawful discrimination and harassment to all forms of discrimination, not just sexual harassment, and to nonemployees, including contractors and vendors; eliminating a longstanding affirmative defense in discrimination cases; and prohibiting requiring employees to sign mandatory arbitration agreements.

The legislation’s provisions have various enactment dates and apply to all employers in the state, regardless of size.

The legislation is partly reflective of Democratic control of both houses of the state legislature, experts say.

“It’s a game changer. It’s huge. It basically converts New York state into California,” said Stephen Stecker, an attorney who represents employers in employment cases with Constangy, Brooks Smith & Prophete LLP in New York.

“This is a seismic shift in New York state human rights law,” said Keith J. Gutstein, Woodbury, New York-based co-chair of Kaufman Dolowich Voluck LLP’s labor and employment law practice group.

“No one really sues under the human rights law as the first stop,” he said. It is usually a piggyback claim when there is litigation under the federal law, but now the state human rights law is “going to be made very relevant.”

Many expect the legislation to be influential, at least in other Democrat-controlled legislatures. “It’ll be influential to other blue states,” said Mr. Stecker. “Red states will more or less stay the same.”

“You can’t look at this in a vacuum,” he said. It must be seen in the “broader context of Democratic states rebelling against the Trump administration.”

But about 15 to 20 other states have already “been passing laws in the same vein,” said Richard I. Greenberg, a principal with Jackson Lewis P.C. in New York, who advises union and nonunion clients on labor and employee relations matters.

“I don’t think it makes states not considering these things suddenly consider these things,” he said.

One particularly significant change in the legislation is it lowers the standard under which employees can charge discrimination from “severe or pervasive” to cases in which it “subjects an individual to inferior terms, conditions or privileges of employment,” he said.

While the harassment no longer must be severe or pervasive, it must be “more than ‘petty slights or trivial inconveniences,’” said Mark S. Goldstein, counsel who is a member of Reed Smith LLP’s labor and employment group in New York. “That makes it a lower bar” for plaintiffs to prove they have been subject to harassment, he said.

“Certainly, I think the state courts will be deluged with claims, because the burden of proving these claims has been radically changed,” said Gerald T. Hathaway, who represents firms in employment and labor matters at Drinker Biddle & Reath LLP in New York.

“It used to be that an employer could sit back and wait for an employee to prove that severe or pervasive harassment has occurred,” he said.

Now, the employee only “has to show some harassment has occurred,” and then the burden goes to the employer to prove the conduct was merely petty slights or trivial inconveniences, said Mr. Hathaway. “These cases are sure to be settled later than they otherwise would have been.”

“The bar is set so low that conversation in the workplaces could trigger a claim that may well be deemed regulation of speech in the workplace by the government,” added Mr. Hathaway, who predicted there will be a U.S. constitutional challenge to the standard.

Another significant aspect of the legislation is that under New York law, it revokes the so-called “Faragher-Ellerth” affirmative defense, which is based on two 1998 U.S. Supreme Court decisions that dealt with supervisor harassment, Burlington Industries v. Ellerth and Faragher v. City of Boca Raton.

The defense has been available for harassment claims under Title VII of the Civil Rights Act of 1964, when the employer could prove it exercised reasonable care to prevent and promptly correct any sexually harassing behavior, and that the employee unreasonably failed to take advantage of any preventive or corrective opportunities provided by the employer.

Previously, if an employer had a policy and a complaint mechanism the employee did not use, the employer had a defense it had acted in good faith. “Now, that kind of goes out the window because an employee doesn’t need to bring a complaint before bringing a claim,” said Daniel J. Moore, leader of the labor and employment practice group at law firm Harris Beach PLLC in Rochester, New York.

Another problematic provision for employers increases the statute of limitations for administrative charges to three years from one, which “puts a much bigger burden on the employer to keep track of all of its files and make sure they can pin down witnesses,” Mr. Moore said.

Among other provisions, the legislation also expands legislation that went into effect in July 2018 that prohibits nondisclosure clauses in the settlement of sexual harassment cases.

Experts advise employers to review and, if necessary, adjust their employment policies to conform to the legislation.

“I’d say it’s a good reminder and opportunity for employers to really take a broad look” at all their anti-discrimination policies, said Devjani H. Mishra, a shareholder with Littler Mendelson P.C. in New York.