Aggro (also commonly spelled 'Agro') is a term used to describe the act of getting the attention of an NPC. This term is associated with role playing games in which there are no random battles, but instead the enemy monsters are visible on the field. When the monster "agros" to a player, it notices that player and changes behavior. Generally, this is in the form of attacking.
The concept of aggro is most prevalent in massively multiplayer role playing games (MMORPGs), and was made famous in a YouTube video of a World of Warcraft raid. During the raid, one character in the party runs ahead, aggro-ing monsters while screams of "Leroy Jenkins!" echo in the background. This untimely aggro leads to the demise of the party.
Monsters may aggro in different ways. A common example is sight. As soon as the player character comes into the field of vision of the enemy monster, it attacks. Some games display this in a cone on a radar, while others leave it up to the player to look for the enemies direction. Other examples include
- Sound - caused when a player walks or runs nearby
- Smell - Cause when a player is in the general area of a monster.
- Magic - Caused when a player uses spells nearby
- Critical or Health - Monsters attack when a nearby player is at a certain health level
- Level - Monsters attack player characters at a certain level based on experience points
- Time - Many MMORPGs feature local day/night systems, and monsters may attack only at night, or between certain hours
- Passive - Monster attacks only when first attacked by player
- Aggressive - Monster attacks as soon as it detects player
- Group or Link - Monster attacks when a monster of a similar type is attacked
Items listed in this list are often combined and have conditional modifiers, such as a monster that attacks players five levels higher and below on sight during the day, and anyone who uses magic at night.
Aggro is important for several reasons. A player that is too weak to fight a certain monster may want to sneak past it to gain access to an item or area. This can best be accomplished by knowing the characteristics of the monster in question, and careful movement of the player character. Also, many games have items or spells, such as Sneak in FFXI, which causes a player to run silently, avoiding sound aggro.
Players may also want to know how to gain Aggro. This is especially important in games with non-instanced dungeons. Competition for a monster that drops a rare and valuable item may result in several players looking to engage it in combat at the same time. A smart player will understand how the monster aggros and use this to his or her advantage to gain control of the monster.
Aggro is also associated with other terms.
- In Final Fantasy XI, aggro is sometimes used interchangeably with the term 'Hate.' Hate is the term describing which player a monster will attack when faced with several choices.
- Pulling, a term used extensively in Final Fantasy XI. One member of a party is designated puller, and this player goes out to gain aggro from the appropriate monster, and then leads this monster back to the safer camp of the rest of the party to be killed.