This time around, some of the things you unlock for one gun can carry over to another. These are universal attachments such as optics, muzzles, ammunition types and underbarrel attachments. For example, if you unlocked a suppressor or 4x scope on an M4, it'll be unlocked and ready to use on another gun that's compatible, such as an AK-47. Then there are attachments such as barrels, lasers, stocks and receivers that are platform-specific. A platform is a subcategory for variants of a gun modeled after a base design: The AK-47 platform includes the default AK-47 (assault rifle), RPK (light machine gun) and AK-74u (submachine gun).

Activision is not just dipping its toes into the popular battle royale video game category. The "Call of Duty" publisher is jumping in, fully committed to take on favorites "Fortnite" and "Apex Legends." The new game, "Call of Duty: Warzone," which launches Tuesday on Sony PlayStation 4, Microsoft Xbox One and PCs, "is the most ambitious environment we have ever built in the franchise's history," said Patrick Kelly, who co-heads Infinity Ward, the studio that developed the game with support from Raven Software. Monday, Activision announced the game, which lets console and PC users play together, in a post on its official "Call of Duty" blog. Free to play online, and available to download starting at 11 a.m.