One of the biggest announcements of E3 2018 was Call of Duty: Black Ops 4 releasing its Battle Royale mode similar to Fortnite and Playerunknown's Battlegrounds. The game mode will be known as Blackout and it will feature one of the largest Call of Duty map ever made which will be 1500 times larger than the Classic Nuketown map and it will have land, air and sea terrains for combat.
Fortnight and Playerunknown's Battlegrounds feature 100 players but the number of players that will be supported in Call of Duty : Black Ops 4 Blackout are still being worked out by the game developer. They want to ensure that the games don't drag too long if the number of players is high or even wrap up too soon due to low number of players.
Verticality will be a big feature in the new map for Call of Duty Blackout since higher grounds give tactical advantage in Battle Royale games. So the map will see higher level terrain as well as skyscrapers and other high structures. There will also be some environmental factors which will result in players moving closer to each other for forced encounters such as the blue wall of death in PUBG and supernatural storm in Fortnite.
According to official description from company "In Blackout, Black Ops comes to life in one massive battle royale experience, combining Black Ops signature combat and the biggest map in Call of Duty history. Play as fan-favorite characters and battle through iconic settings from the Black Ops universe. It’s a collision course bringing together the worlds of Black Ops in an all-out survival and elimination experience featuring weapons; equipment; land, sea, and air vehicles; RC-XDs; traps; and even Zombies in an experience that is uniquely Black Ops."
Blackout will also feature a unique timed health system where you can heal yourself to full health after enemy encounters. There will also be multiple types of health packages such as medkits. According to the game developer, Blackouts will be Battle Royale gameplay done in a uniquely Call Of Duty way.