College students have heard a similar refrain for years in campaigns to stop sexual assault: No means no.

Now, as universities that are facing pressure over the handling of rape allegations adopt policies to define consensual sex, California is poised to take it a step further. Lawmakers are considering what would be the nation’s first measure requiring all colleges that receive public funds to set a standard for when yes means yes.

Defining consensual sex is a growing trend by universities in an effort to do more to protect victims. From the University of California system to Yale, schools have been adopting standards to distinguish when consent was given for a sexual activity and when it was not.

Legislation passed by California’s Senate in May and coming before the State Assembly this month would require all schools that receive public funds for student financial assistance to set an “affirmative consent standard” that could be used in investigating and adjudicating sexual-assault allegations. That would be defined as “an affirmative, unambiguous and conscious decision” by each party to engage in sexual activity.

Silence or lack of resistance does not constitute consent. The legislation says it is also not consent if the person is drunk, drugged, unconscious or asleep.

Lawmakers say consent can be nonverbal, and universities with similar policies have outlined examples as maybe a nod of the head or moving in closer to the person.

Several state legislatures, including Maryland, Texas and Connecticut, introduced bills in the past year to push colleges to do more after a White House task force reported that 1 in 5 female college students is a victim of sexual assault. The U.S. Education Department also took the unprecedented step of releasing the names of schools facing federal investigation for the way they handle sexual-abuse allegations.

But no state legislation has gone as far as California’s bill in requiring a consent standard.

Critics say the state is overstepping its bounds. The Los Angeles Times, in an editorial after the bill passed the state Senate 27 to 4, wrote that it raises questions as to whether it is “reasonable” or “enforceable.” The legislation is based on the White House task force’s recommendations.

“It seems extremely difficult and extraordinarily intrusive to micromanage sex so closely as to tell young people what steps they must take in the privacy of their own dorm rooms,” the newspaper said.

Some fear navigating the murky waters of consent spells trouble for universities.

“Frequently these cases involve two individuals, both of whom maybe were under the influence of alcohol or drugs, and it can be very tricky to ascertain whether consent was obtained,” said Ada Meloy, general counsel of the American Council on Education, which represents college presidents.

She said schools need to guarantee a safe environment for students, while law enforcement is best suited for handling more-serious sexual-assault cases.

John F. Banzhaf III, a George Washington University Law School professor, says he thinks having university disciplinary panels interpret vague cues and body language will open the door for more lawsuits.

The legal definition of rape in most states means the perpetrator used force or the threat of force against the victim, but the California legislation could set the stage in which both parties could accuse each other of sexual assault, he said.

“This bill would very, very radically change the definition of rape,” he said.

University of California at Berkeley student Meghan Warner, 20, said that’s a good thing. She said she was sexually assaulted during her freshman year by two men at a fraternity but did not report it, because she believed “that unless it was a stranger at night with a weapon who attacked you when you were walking home, that it wasn’t rape. It’s just a crappy thing that happened.” She now runs campus workshops to teach students what constitutes consent.

“Most students don’t know what consent is,” she said. “I’ve asked at the workshops how many people think if a girl is blacked out drunk that it’s okay to have sex with her. The amount of people who raised their hands was just startling.”

Defining consent may be easy to do on paper, said Laura Nguyen, a 21-year-old San Diego State University senior, but “we’re talking about college students out at night, and the reality is there’s not just yes or no. There is a lot of in between. I really think it depends on the situation.”

The legislation initially stated that “if there is confusion as to whether a person has consented or continues to consent to sexual activity, it is essential that the participants stop the activity until the confusion can be clearly resolved.”

After some interpreted that as asking people to stop after each kiss to get a verbal agreement before going to the next level, the bill was amended to say consent must be “ongoing” and “can be revoked at any time.”

“California needs to provide our students with education, resources, consistent policies and justice so that the system is not stacked against survivors,” state Sen. Kevin de Leon, a Los Angeles Democrat, said in promoting the bill.

Supporters say investigators would have to determine whether consent had been given by both parties instead of focusing on whether the complainant resisted or said no.

Denice Labertew of the California Coalition Against Sexual Assault said the bill fosters a cultural change: “There’s a lot of criticism around affirmative consent because it requires us to change the way we normally think about this.”