Difficulty

Difficulty can be toggled via the Options menu in Minecraft. Changing this option has a direct impact in the gameplay itself. There are currently four difficulties in the game.

Possible difficulties
Notch said in his blog that he would add the "hardcore" difficult. The rules would be You die, the world is deleted and it is created a new world. The idea came to Notch from a Minecraft gameplay blog in the PC Gamer site (blog)

Trivia

 * Notch made a tweet on October 22nd, 2010 where he states that "I'm changing "difficulty" to "realism". Lowest setting = creative. Highest setting = starve"