Attack is one of the core attributes for characters in Diablo III. It governs the amount of damage a character does in all attacks, physical and magical.
All attributes have changed since their original conception. Bashiok made an announcement[1]about these changes on the Battle.net forums on December 20, 2010:
Attack: Increases damage
- This stat will be a universal damage increasing stat for all classes to prevent confusion about what you should increase to do more damage.
- We realize that ‘Attack’ is less flavorful than ‘Strength’ and ‘Willpower’, but we feel the pros of understanding clearly how to build your character outweigh that con.
- This stat has no secondary effects.
More details on exactly how Attack will work in Diablo III are not yet known. What is known is that attribute points are not assigned by the player; they are auto-assigned. See the relevant section in the attributes article.