Following on from this weekend’s free trial of Fallout 4, PC owners will be able to get their hands on the entire set of map DLC for Call of Duty: Black Ops 3 next month. All four packs will be available to use from 6pm on May 30th and will continue to be free to use for the following thirty days.
Obviously you are going to need Black Ops 3 to use them, and it’s only the map packs, Awakening, Eclipse, Descent, and Salvation, that are available, not weapons or zombies DLC. If you already own the maps then you will get double XP instead.
Source: Call of Duty