Real-World Injuries
All the actions that a player can take in a battle royale game type suddenly involve new considerations if they incorporate an injury system like the one found in games like DayZ. A common example is fall damage. Currently, anyone playing PUBG who leaps from a building only has to suffer damage. With a real-world injury system, jumping out a third story window would not only take away a chunk of health, it would leave the player with a broken leg that would immediately hamper movement.
With this system, more players would probably fall victim to their wounds instead of the actions of their competitors. Running out of stamina while swimming would cause drowning. Forgetting to eat or drink would cause starvation or dehydration. One gunshot wound would cause a player to bleed out in minutes without some sort of medical care. Currently, the opening minutes of a PUBG game are spent hunting for weapons and armor. With this injury system, things like medicine and food would suddenly become the most valuable items to horde.