RPG Law: Health (Red), Poison (Green) and Mana (Blue)
Health is used on objects to decide when they are dead. The object in this case can by anything that can die or be destroyed. For example a object can be a airplane, a chair, a enemy or player character. There are a number of common systems in use for health and each system list a example game that use it. This is about the gameplay function of the system and each one can be shown in a number of different ways to the player. For example a x/y system can be shown as a bar, blood on the screen or a blue power spine on the player avatars back.
One - (Silkworm)
In this system the player dies the first time he gets hit. Cold and unforgiving and often used in arcade games that was made to make the player and his wallet suffer. For this to work the player need to be able to avoid or counter any attack. Projectiles moves slow so they can be avoided and attacks are telegraphed so the player can learn when to move to avoid them.
Containers - (Zelda)
Like hearts and each hit removes one heart.
x/y or bar - (Doom, Metroid Prime 3)
The player have a max of y hit points and his current hit points are x. If he gets hit he loose z hit points depending on a number of factors like the weapon that hit him or his armour. Often shown as a health bar and it's common in RPG's where you can get more health.
There are a number of regenerating versions in use for x/y style health.
Full - (Halo 2)
Full regenerations wait a while until the player is safe to return the player to max health again. This removes the need for health kit and resets the state of the player before the next fight. Not uncommon in cover based shooter where the player spends a lot of time behind small concrete barriers.
Min Regenerating Bar - (Wolfenstein The New Order)
A min bar regenerates back to a small minimum value when the player is safe, ex 20%. That way one can be certain that the player has at least a small amount of serviceable health for the next encounter so one does not have to put health kit after each fight.
Segmented Regenerating Bar - (Chronicles of Riddick: Escape from Butcher Bay)
The health bar is split into a number of segments at ex 25,50,70 and 100%. A while after damage the bar will regenerate the segment it is on.
In a component health system the object is made up of multiple parts. The overall state of the object depends on what component is damaged and the state of the other components. One example is a tank that can have components such as engine, fuel tank and cannon. A hit to the cannon destroys the tanks ability to shoot but will not kill it. A fuel tank hit will destroy the tank directly.
With overcharge the player can gain more then his max health for a short while. Ex by picking up extra health pack that will boost the health up to 150 in a system with max 100. In that case there can be a overcharge limit or that the health will drain back to the normal max level.
How Games Do Health | Game Maker's Toolkit - 2016
Alternatives to Hit Points - 2015
What alternatives to hit points are there for abstracting wounds? - 2013