Normal (difficulty)

The Normal difficulty is the easiest of all difficulties.

Diablo/Hellfire
Characters created in the original Diablo start in Normal difficulty. Excluding a certain trick that requires an already leveled multiplayer hero, Normal difficulty is the only difficulty accessible in the original game if the hero is in singleplayer. Multiplayer heroes must grow in power if they wish to start/join a game in the harder difficulties: The Hellfire expansion pack permits any hero access to Nightmare and Hell difficulties, even if he/she is a singleplayer hero. In addition, if the hero is in singleplayer, the game does not require them to grow in power for these levels. Choosing to go into a higher difficulty early on, however, is best considered as insanely suicidal or insanely bold, as the hero will have quite a hard time surviving in the depths of the labyrinth.
 * For Nightmare difficulty, players must be level 20 or above.
 * For Hell difficulty, players are required to be level 30 or above.

Diablo II
Characters that are created in Diablo II will start in this difficulty level. Hirelings and Summons deal 50% damage to Act bosses on this difficulty. If a character kills Diablo in non-expansion they will gain a new title and the option to venture into Nightmare upon starting the game. Expansion pack players will receive the title upon successfully defeating Baal, as well as the opportunity to adventure in the Secret Cow Level.

In classic (playing without the expansion, either by not installing Lord of Destruction or leaving the checkbox blank during character creation) defeating Diablo will grant a specific title:
 * Hardcore: Male will be Count and Female Countess
 * Softcore: Male will be Sir and Female Dame

If it is an expansion character, killing Baal in Act 5 will grant the following titles:
 * Hardcore: Male and Female will be Destroyer
 * Softcore: Male and Female will be Slayer

Diablo III
There is nothing special about this difficulty. It can be thought of as the default from which all other difficulty levels are calculated.

It is the lowest difficulty possible. In the demo only one other difficulty is possible: Hard