Save The World / Battle Royale skins; are they interchangeable?

No, the skins you have in BR are not interchangable between the skins you get in STW.

The only thing that carries over between both game modes are:

  • V-Bucks
  • Banner Icons

Save The World "Skins" are not interchangeable, and they are also not skins. In Save The World, the skins are actually different heroes with different abilities and stats. A lot of Heros in save the world will come into Battle Royale which you can buy for V-Bucks in the battle royale shop.