Lots of Mabinogi combat/range skill are for one to one combat. So the game AI has to provide a rule that a player can combat without the frustration of fighting all surrounding mobs with 1:1 skills. But it also has to provide certain challenges to give the players incentive to build their charaters.

When you play in a dungeon, you will notice that there could be lots of mobs at a time in a room but only few of them recognize you and try to attack you while other mobs pretend as if they didn't see you at all.

That is because those mobs are under the control of aggro rule. Aggro is a way how particular mob recognizes you.

Aggro is most important in single player combat. Mobs may switch the target if there are multiple players (including your own pet) in their aggro range.

1. Aggro state.
Just looking at the surface, there are 4 states of a mob's aggro towards you.
- No aggro - The mob just behaves that it didn't see you at all.
- Supporting - The mob displays a red ? mark on its head and follows you.
- Stunned - From the surface, looks same as supporting.
- Aggro - The mob displays a !! mark on its head and attacks you.

Obviously, there would be more states internally in the mob's AI mabinogi gold. The aggro state of a mob that is walking right around you would be different from the one of a mob that is very far away from you.

When you have been in close radius with mobs,
- Some mobs switch from no aggro state to aggro state automatically.
- Some mobs switch from no aggro state to supporting state automatically.
- Some mobs stay in no aggro state forever.

If you directly attack a particular mob, that mob will switch to aggro state regardless of which state it was previously in.

2. Aggro type.
Each type of mob has particular aggro type. In general they are categorized into two types.

- M:1
This means that only M number of mobs from the same type recognize you.
M could be set to very high number to make it look like all of the mobs will attack you when they see you.
example) goblin has 1:1 aggro type so only one will recognize and attack you at a time. Goblin archer has 2:1 aggro type so only two of them will attack you at a time.

- M+N:1
This means that only M number of mobs from the same type recognize you while there would be N supporting mobs.