https://www.gamespot.com/articles/grab-some-free-battlefield-dlc-on-ps4-xbox-one-and/1100-6460887/

Anyone with a copy of Battlefield 1 or Battlefield 4 lying around on your shelf or hard drive can pick up some free DLC right now for a limited time. On PS4, Xbox One, and PC (through Origin), publisher Electronic Arts has made Battlefield 1's Apocalypse expansion free through August 6. Meanwhile, during the same time period, Battlefield 4 players can pick up the China Rising and Naval Strike DLC packs without spending any money. Seeing as these expansions normally cost $15 each, that's a nice deal to grab before they go back to regular price.

Battlefield 1's Apocalypse DLC adds five multiplayer maps to the game, including real-life WWI battlegrounds Passchendaele, Somme, and Caporetto, as well as the aerial combat maps London Calling and Razor's Edge. Also included are a number of new vehicles, gadgets, and weapons, like the Assault class's AA Rocket Gun.