"The truth is that an assault weapons ban is a very important part of the solution -- and it is also much tougher to pass," said Mark Glaze, director of Mayors Against Illegal Guns.
Restrictions on high-capacity ammunition magazines are also seen by some as an easier lift politically than banning assault weapons.
The National Rifle Association adamantly opposes universal background checks, as well as bans on assault weapons and high-capacity magazines -- all measures that would require congressional approval. The NRA and other pro-gun groups contend that a culture that glamorizes violence bears more responsibility for mass shootings than access to a wide range of weapons and ammunition.
In a 2009 report, the American Academy of Pediatrics declared, "The evidence is now clear and convincing: Media violence is one of the causal factors of real-life violence and aggression."
The report focused on all types of media violence. But for video games in particular, the pediatricians cited studies that found high exposure to violent ones increased physical aggression at least in the short term, and warned that they allow people to rehearse violent acts. On the other hand, it said friendly video games could promote good behavior.
A wide spectrum of the video game industry was represented at the meeting with the vice president, including the makers of violent war video games such as "Call of Duty" and "Medal of Honor" and a representative from the Entertainment Software Ratings Board, which sets age ratings that on every video game package released in the United States.
The vice president met Thursday with representatives from the entertainment industry, including Motion Picture Association of America and the National Cable & Telecommunications Association. In a joint statement after the meeting, a half-dozen said they "look forward to doing our part to seek meaningful solutions" but offered no specifics.
Biden, hinting at other possible recommendations to the president, said he is interested in technology that would keep a gun from being fired by anyone other than the person who bought it. He said such technology may have curtailed what happened last month in Connecticut, where the shooter used guns purchased by his mother.
The vice president has also discussed making gun trafficking a felony, a step Obama can take through executive action. And he is expected to make recommendations for improving mental health care and school safety.
"We know this is a complex problem," Biden said. "We know there's no single answer."
The president plans to push for the new measures in his State of the Union address, scheduled for Feb. 12.