Battlefield 4: Legacy Operations is a free expansion and content update for Battlefield 4 released on December 15, 2015. The expansion includes an updated version of the Battlefield 2 map, Dragon Valley, and was released alongside the Winter Patch content update for Battlefield 4.
Legacy Operations is only available on PC, PlayStation 4 and Xbox One. It's the first time the new Battlefield 4 content is not released on PlayStation 3 and Xbox 360. The accompanying Winter Patch was still released on the 7th generation consoles.