Damage

Damage from attacks or natural causes will subtract hearts from this total. When the total reaches zero you die. When a mob dies, it drops items specific to that mob, Players drop their inventory when they die. Damage is measured through a health gauge and monitor. Each full heart contains two halves, one hit point each (full health is 20 hit points).

Armor will absorb damage and reduce the number of hit points subtracted from the player's (or mob's) health (damaging the armor instead).

Dealing damage
Players can deal damage by hitting mobs or other players with items at close (melee) range. A large majority of items only deal damage. Weapons can be crafted for the express purpose of dealing more damage. Swords are crafted for this purpose. While swords do not extend attack range, they deal significantly more damage than with any other item or tool. Axes, pickaxes, and shovels also deal more damage than bare fists however, with hoes doing the same damage as fists, as detailed on the Weapons page. While falling, melee attacks deal a critical hit (up to 50% + additional damage, rounded down to the nearest hit point).

Arrows (shot by holding and releasing right click when wielding a Bow), snowballs, splash Potions, and chicken eggs are the only ranged weapons in the game. Snowballs only inflict damage on Blazes and the Ender Dragon, while eggs do no damage at all, but still knock mobs back as if they had been damaged. Splash potions can be thrown, inflicting various effects depending on the potion.

The Flint and steel allows the player to light a block on fire, which causes all players and mobs that touch the fire to be set on fire, with the exception of certain fireproof monsters such as Zombie Pigmen, Magma Cubes, Blazes, Ghasts and Wither Skeletons. Players and mobs that are ignited stay alight until hit points of damage is dealt or until they touch water. Likewise, contact with Lava also ignites players and mobs.

TNT is currently the only controllable explosive in Minecraft and is obtained by crafting sand and gunpowder.

The below values detail the damage dealt per hit using various items. Note that weapons and tools in 1.8 dealt more damage, and that critical damage is not consistent.

Critical hits


'Critical hits' are attacks that deal extra damage compared to regular attacks. Critical melee strikes, regardless of the weapon used, cause small star particles to fly out of the target who was critically hit. "Critical arrows", which occur when the bow is fired fully charged, leave a trail of the same small star particles as they fly through the air. Critical hits affect all damageable entities including players, mobs, paintings, boats and minecarts.

In melee, a critical hit occurs when a player attacks a mob while falling. The attack deals a random amount of additional damage, up to 50% more (rounded down) plus one heart. This can be done by jumping. It can also be combined with sprinting to knock back the mob, although there is no extra knockback for a critical hit.

In an abandoned mine shaft, a player may choose to jump into a cobweb. At the cost of mobility, the player will be granted a major damage increase, as cobwebs greatly extend the time the player falls. This same tactic can also be used when descending in water.

More specifically, the requirements for a melee critical hit are:
 * The player must be falling
 * The player must not be on the ground
 * The player must not be on a ladder/ vine etc.
 * The player must not be in water
 * The player must not be affected by the Blindness Potion
 * The player must not be riding an entity

This is a chart cross-referencing weapons with materials to find the maximum amount of damage dealt from critical hits in version 1.3.2:

As fists and arrows do not have a "material", their damage is constant. Although Hoes are tools, they are not counted as weapons and have the same effect as fists (no durability loss and same damage)

Damage immunity
After sustaining damage from any source, a mob will turn red in color for a short period of time. During this period, any other incoming damage will not be counted against the mob's total health. For instance, if you attack a mob with a Sword repeatedly hitting the mouse button, the sword's rate of fire will exceed the mob's allowable rate of incoming damage, and several of the attacks will not damage the mob even if they land. (It is recommended to wait for a mob to be hittable again before swinging your sword, as the durability still goes down, whether or not you dealt damage). However, if a mob or player is recovering from damage and then receives higher damage, it gets counted. Players are also subject to damage immunity.

Damage inflicted by mobs
The damage Mobs deal to players is affected by the difficulty of the game. The below values represent the amount of damage taken per hit.
 * This only applies to mobs attacking the player. Mobs attacking other mobs (wolves, iron golems, etc.) always deal the 'Normal' damage listed, regardless of difficulty.
 * Values for the Creeper and Ghast assume the player is directly adjacent to the explosion.
 * The damage of Slimes and Magma Cubes depends on their size. Tiny-sized Slimes, while hostile, are unable to do damage directly.

Knockback
When receiving damage from a hostile mob you will also be knocked back. The resulting disorientation and loss of control should not be underestimated, as it is possible to be knocked back over a cliff or into lava, both of which are potentially fatal.

Players can also be nudged by neutral mobs walking into them, but note that this effect was removed in the 1.3.2 update. The push is not nearly as powerful as a hostile mob's knockback, but can still send the player off of a cliff or into lava, or fall off a cliff into lava. Knockback can also be caused when a player throws a chicken egg or a snowball at a mob, useful for making traps. As of Beta 1.8, sprinting while attacking a mob causes extra knockback. Players/Mobs riding an entity (typically a boat, a minecart or a pig) never receive any knockback when attacked.

Natural damage
Besides mobs, players can take damage from several other events in Minecraft.

Lightning damage
As of Minecraft 1.0.0, Lightning will do two damage, even through armor. Lightning strikes on the player are very rare, and only occur during thunderstorms. It is most likely that when the player gets hit by lightning they will be set on Fire.

Fall damage
You receive damage when falling from certain heights. The amount of damage received depends on the total height of a drop, and it is possible for a player to die upon falling to the ground. Armor does not reduce fall damage [Except for boots with the Feather Falling or Protection enchantments].

Fall damage can be calculated using this formula:

FD = number of blocks - 3

In other words, falling 4 blocks causes damage. From 5 blocks, damage. From 6 blocks, points are lost and so forth with, assuming full health, a 23 block fall being fatal (23 - 3 = 20 damage = 10 hearts of damage).

Mobs (other than chickens, ghasts, snow golems, blazes, magma cubes, iron golems, ocelots, bats and, presumably, the ender dragon and wither) suffer fall damage as well.

In some cases, it is possible to avoid falling or otherwise survive a fall. Falling damage is only dealt after a height of three blocks.


 * Sneaking (default ) will prevent you from falling off most blocks.
 * Landing in Water will reduce fall damage. Depending on the height of the fall, it needs at least 2 blocks of water to reliably nullify the fall damage; however, even 1 or 2 blocks may sometimes do so.
 * Moving into a Ladder or Vine's area of effect during free fall will reduce vertical velocity to normal ladder descent speed and no damage will be taken.
 * Moving into water during free fall will also reduce velocity.
 * It is dangerous, but sometimes useful, to descend cliffs by walking off a cliff while in a boat. Exit the boat before impact, and you will only take damage for the distance fallen since exiting the boat.
 * Jumping counts as falling for 1.5 blocks, therefore adding to your total fall damage, so keep this in mind when trying to avoid fall damage.
 * If falling next to a wall, emptying a bucket of water against the wall a few blocks from the ground can often save your life.
 * Wearing armor that is enchanted with feather falling or protection reduces fall damage based on the level of the enchantment.
 * Throwing an Ender Pearl and teleporting will reset your velocity, and you will only take damage from the pearl . This works best if you throw the Ender Pearl directly at the ground below you to guarantee the pearl hits the ground before you do.
 * Falling into a spider web prevents all fall damage. (Test have been taken by jumping down a tower taller than 20 blocks into a one block thick layer of spider web.) If you place a spider web block beneath you fast enough while approaching the ground you can survive.

Drowning


When a player runs out of air underwater, they will start drowning and will take approximately /sec. Mobs can drown as well, though they usually do not, as all mobs (besides iron golems and slimes) attempt to swim upward when in water.

While mining, consider keeping at least one placeable solid block ready somewhere on your toolbar (such as Dirt or Cobblestone) for quick access. If you mine into a spring (or worse, the ocean), you should be able to place the block in the hole to prevent drowning.

If you place a torch on a vertical surface next to you at head height whilst underwater, you create an air bubble which lasts for the split second it takes the water to destroy the torch, thus refilling your oxygen meter without resurfacing. Ladders, signs, fences, trapdoors, doors and sugar cane can create permanent air bubbles underwater. You can also scoop up some water with a bucket to achieve the same effect, or destroy the block directly above you, if there is one.

When drowning your oxygen goes down and eventually your hearts while under water.

Suffocation
Suffocation is when a player or a mob is unable to breathe due to his upper half being inside of a block. They will lose every half-second. Due to sand and gravel falling, it can easily cover the player. In first person mode, the player's screen will be blackened when suffering from this condition thus disabling them to see what is happening. In third person mode, the view will automatically switch to first person mode.

When inside a block, the player can easily step out of it as the blocks do not prevent their movement.

The usual ways to get one's head inside a block are:

It's worth noting that the player will not suffocate in glass, or indeed in any transparent block. Leaves from a grown Sapling will not suffocate you, even if you're on Fast graphics (which makes leaves appear solid).
 * Sand or Gravel falling into the space the player or mob occupies.
 * Riding a Boat or Minecart into a one-block-high space.
 * Riding a pig into a two- or one-block-high space.
 * Standing where a tree just grew from a sapling.
 * Standing where a huge mushroom just grew from a mushroom.
 * Standing where an Exit Portal just spawned after killing an Ender Dragon.
 * Having a block pushed onto your head with a Piston
 * Throwing an Ender Pearl into a one block space
 * Sleeping in a bed that is surrounded by blocks.

Starvation
When the food bar reaches zero, the player will take damage every four seconds. The player stops taking starvation damage when the player eats or the health bar drops to on easy mode or  on normal mode. In hard mode, the damage will not stop until the player either dies, or eats something.

Cacti
Touching cacti will cause a player or mob to take damage, and rapidly continue taking damage if he or she continues to stand on or next to it.

Lava
By far the most dangerous natural occurrence (except for the unlikely case of a player falling into the void), players and mobs will take damage from contact with Lava extremely fast ( per hit), and stay on fire even if they exit it ( point per hit for 15 hits ( total damage) or until extinguished with water). If players do not have a water source available, they will die quickly.

While mining, consider keeping at least one placeable solid block ready somewhere on your toolbar (such as Dirt or Cobblestone) for quick access using your mouse wheel. If you mine into a lava pool, you may be able to place the block in the hole and so prevent burning. It is possible to keep a fire-resistance potion at all times so you can prevent from dying in lava, although if you fall in the lava, you won't be able to use the potion in time. Instead, try using a splash potion of fire-resistance.

Poison
Cave Spiders will poison players when they bite (only in normal and hard difficulty). Eating a Spider Eye, Poisonous Potato, or drinking/being hit by a potion of poison will give the same result. While poisoned, the hearts in the health meter turn from red to an olive yellow and continually damages the player by per second until the poison wears off. The poison itself cannot kill the player, but it can always reduce them to 1 hit point, thus leaving them very vulnerable to damage from other sources. Poison can be cured by drinking milk from a bucket.

The Void
In creative mode, if one were to break through the bedrock barrier found at the bottom of worlds, the Void can be seen. As of Beta 1.8, the void is completely black, and emits the same particle effect of those underwater. Players in the void, below height -64 will take damage at a rate of about per half-second.

You can also fall into void in The End.

The only way to stop the Void Death is to use third party mods, like Tekkit Quantum Armor which removes 100% damage via charging it with EU. "It uses EU charge to absorb 100% of damage taken, protecting the player from everything until it runs out of charge." (Source: Tekkit Wiki)

Trivia

 * Critical hits can be done while reflecting a Ghast's fireball, but won't change the damage or speed of it.
 * In Creative mode, attacking a mob while flying after having flown downward will get a critical hit.