- Killed by a hostile mob
- Fall damage
- Fire damage
- Suffocation (either in Water or in solid blocks)
- Killed by another player
- Use of /kill command
- Falling out of the world (or Void damage)
Upon death, different things may happen, dependent on gamerules and difficulty setting.
In survival mode, when the difficulty is set to Peaceful, Easy, Normal or Hard, the player will have the option to respawn when they die. The player will appear at their Spawn point, which will either be the original area they appeared when they first entered the world, or beside the most recent Bed they slept in (usually without anything in their Inventory). In Hardcore Mode, however, there is no option to respawn. The only options are to either delete the entire Minecraft world, or to switch to Spectator Mode.
The only gamerule that affects death is "keepInventory". If enabled, the player will respawn with all of their inventory. The alternative is having to run back to where they died to reclaim their items before they Despawn.
In Survival and Adventure mode, one can die by any of the methods mentioned above. In Creative Mode and Spectator Mode, however, the user can only be killed either by the /kill command or by exposure to the Void.
A mob can die in any of the ways a player can die, with some exceptions. Whenever a mob dies, their skin flashes red for a brief moment, they fall over on their side, and vanish in a wisp of smoke as they Despawn. They may leave behind some Items and Experience Points on the ground where they died.
One exception to the typical death effect is when an Ender Dragon dies. When killed, it floats up slightly and breaks down into beams of light, creating as End Gateway, which may be used to escape the End.