It requires a background check and California Department of Justice authorization to purchase ammunition, prohibits possession of high-capacity ammunition magazines over ten rounds, levies fines for failing to report when guns are stolen or lost, establishes procedures for enforcing laws prohibiting firearm possession by specified persons, and requires California Department of Justice's participation in the federal National Instant Criminal Background Check System.

[3] A September 2016 poll from USC Dornsife / Los Angeles Times showed 64% percent of registered voters in favor of Proposition 63, 28% opposed, and 8% unknown.

[8][9] Benitez stated that various violent crimes were far more common than mass shootings, and people can use firearms to defend themselves from them providing the law allows it, giving several examples in the first few pages of the opinion.

Californians approved the proposition and added criminalization and dispossession elements to existing law prohibiting a citizen from acquiring and keeping a firearm magazine that is able to hold more than 10 rounds.

On Friday, September 22, 2023, Benitez declared the California's ban on magazines that hold more than 10 rounds of ammunition to be unconstitutional for the second time, saying it violated the Second Amendment rights of firearm owners.