Definition: Aggro is a contraction for the word "aggression" which is used as both a noun and a verb in roleplaying games. NPC monsters in RPGs will become hostile toward you if you attack them, or, in some cases, if you get within a certain range of them. When your character is attacked, you are said to "have aggro." You are said to "aggro the mob" when you trigger an attack.
Aggro is also used quantitatively to describe how much hate a particular mob has toward a particular player. Typically, a hostile monster will attack whichever player has inflicted the most damage on it, although the equation by which these things are calculated can be very complex. In some games it is helpful to allow one player to do a lot of damage to a monster before other players join in, so that the former can accumulate aggro, and thereby keep the monster from attacking more vulnerable party members.
Also Known As: aggression, hate, threat
Examples: If you accidentally aggro those demons we'll all be dead.
