Just like in Call of Duty’s normal multiplayer perks can give you specific stat boosts in the Blackout Battle Royale Mode. These green boxes will be found pretty frequently across the map and they have a bunch of different buffs that you can use on the battlefield. Using Perks in Blackout Battle Royale can be done through the Quick Inventory Menu or through the Main Inventory Menu.
The Quick Inventory Menu in Blackout mode will allow you to use perks or equipment, as well as select which healing items you want to have equipped. To use perks, simply press up on the d-pad and then select the perk you want. If you have more than one perk in your inventory, you can use the left and right d-pad directions to tab through the perks you have and select the one you want. Press and hold the Square Button (PlayStation 4) or X Button (Xbox One).
Perks in Blackout Mode aren’t permanent. If you use a perk it will only be active for a limited amount of time. Once you’ve got a perk equipped, you’ll be able to see a timer counting down that shows you how long you have left to get the benefits of that perk.
A lot of the common perks that you find in normal Call of Duty multiplayer can be found out in the Battle Royale mode.
If you want to take the manual approach to using perks, you can do so by pressing the Options Button (PlayStation 4) or Start Button (Xbox One). There you can access you inventory screen, select the perk you want and use it from there by pressing the square button.