Health/HP is a property of Humanoid objects that determines the current vitality of that Humanoid. By default, a Robloxian has 100 Health. Whenever health drops to 0, the Humanoid dies, all joints in the model that houses the humanoid breaks, and the Died event fires. If the head is detached from the torso, the Humanoid's Health is automatically set to zero. In game , by default when Health drops to 0 in any way except falling from a baseplate, the humanoid will make an "uuhhh", or what is mostly referred as the "oof" sound. When a Humanoid being thrown at high speed then the Health drops to 0, the death sound becomes more low-pitched or high-pitched depending on how fast the humanoid is being thrown, due to RollOffMode properties. Sometimes, it will fall as a ragdoll if the dev decided to do so.
Once a player dies (the player's body parts breaking apart, and their accessories and gear they would've been holding out falls off), they normally must wait 5 seconds to respawn . There is an occasional glitch where the player's body parts do not break apart upon losing all of his/her health.
A script is added by default that causes the health of player characters to regenerate automatically. By default it restores 1% of the maximum health(1) every second. By using scripts, users can alter how fast the health is restored, if it regenerates at all, or make the health gradually reduce over time, among other things. Sometimes it doesn't heal.
(e.g. Pirate in Boxing Simulator has 3000 HP and wanders through its island.The Boss Bloxian has 750 HP in Battle as a Giant Boss! and does not heal. (Neither than the Boss Hunters)
Roblox's health GUI was a bar representing a player's character's current Health (the size of the green or red bar) and MaxHealth (the size of the current health bar is determined in the proportion of MaxHealth). The Health GUI is placed near the center of the bottom of the Player's screen. The standard health GUI can be edited and even removed by Scripts and LocalScripts.
As of 2015 the Health GUI is no longer a separate GUI but is integrated into the default Roblox's in-game interface.
Since the beginning of Roblox, there has been a hard-coded GUI for the health bar (as in one which could not be modified by the user). As of the introduction to the Lua interface, the current health GUI now appears instead.
At first, the health bar was on the right side of the screen, which is a green bar that turns red when health lowers. Also, blue text saying "Health" is under it. In the 3rd version, it was made taller. The font "Comic Sans" was also replaced with a different font.
In the fourth version, it changed completely, it is now on the bottom and white text saying "HEALTH" is inside it. Also, when a large amount of health is reduced, the health bar flashes red, when the player's health was low, the health bar turned red. A notable change is what looks like blood when the player dies instantly or loses a large amount of health appears on the corners of the screen. In the fifth version, the health bar no longer blinks when a large amount of health is lost, and the font was also changed.
For the sixth version, first implemented on August 27, 2014, the health bar was simplified with a lighter green color and with rounded edges. The word "Health" was removed, and the bar will now look white when a player loses all of their health.
In 2015, the seventh version made it so that the health bar was put in the leaderboard, below the player's name, with square edges and is thinner than before. In 2017, the eighth version and current one made it so that no health bars will appear when the health is equal to the maximum health of a Humanoid, this includes the default health bar that shows the player's health and the health bar that appears above humanoids.