Aggro

Aggro, short for aggression, is an invisible statistic that determines the distance at which enemies will begin to attack the player.

All enemies target the player based on criteria set in their AI. Most will constantly try for a target, while others may only target if the player is in water, for example.

Armor and other items that "increase/decrease enemy targeting" cause enemies to consider a player to be closer or farther away than they actually are. Certain accessories, armor, and other sources in the Calamity Mod affect Aggro.

Source	Aggro change
Rogue stealth	-3 per point of stealth
Colossal Squid	-750 (while being eaten)
Eclipse Mirror	-700 (also reduces Abyss detection)
Abyssal Mirror	-450 (also reduces Abyss detection)
Reaver armor (Reaver Headgear)	-200 (also reduces Abyss detection)
Mirage Mirror	-200
Victide armor (Victide Shellmet)	+200
Aerospec armor (Aerospec Helm)	+300
Statigel armor (Statigel Helm)	+400
Daedalus armor (Daedalus Helm)	+500
Reaver armor (Reaver Helm)	+600
Hydrothermic armor (Hydrothermic Helm)	+700
Tarragon armor (Tarragon Helm)	+800
Bloodflare armor (Bloodflare Ram Mask)	+900
God Slayer armor (God Slayer Horned Greathelm)	+1000
Auric Tesla armor (Auric Tesla Royal Helm)	+1,200

Notes

• Aggro reductions of -750 (or more) nearly guarantee the player will not be targeted.
• Enemies in the Abyss have their own unique detection radius system, independent of Aggro, which can be affected by items such as Anechoic Coating and Abyssal Diving Suit as well as the Luminous Corvina enemy.
  • Despite this, being eaten by Colossal Squid decreases Aggro rather than the Abyss creatures' unique detection radii.