Threat Level, or popularly known as Aggro, defines how dangerous a non-player character perceives a target to be and thus the importance of attacking that target. NPCs will prioritize attacking the target with the highest threat level that is within range.
Increasing Threat Level[]
Abilities[]
The following abilities will temporarily increase threat level:
Atlas' 
Rumblers with 
Titanic Rumbler: Recasting the ability will taunt enemies instead.
Gara's Spectrorage: Creates a carousel of mirrors with high threat level and reflects damage back to the attacker.- Khora's Strangledome: Creates a dome that captures and ensnares enemies; captured enemies are susceptible to friendly fire, with high threat level.
- Loki's Decoy: Creates a decoy with high threat level.
- Mirage's Hall Of Mirrors: Creates clones of Mirage around her with high threat levels.
- Nekros' Shadows Of The Dead: Creates shadow versions of recently fallen enemies with high threat levels.
- Nidus's Ravenous: Creates maggots with high threat levels.
- Nyx's
- Octavia's Resonator: Creates a mobile Resonator with high threat level.
- Revenant's Enthrall: Converts an enemy into a Tenno-aligned thrall that turns on their former allies, with high threat level.
- Saryn's Molt: Creates a decoy with high threat level.
- Titania's Razorwing: Creates Razorflies with high threat levels.
- Wukong's Defy: Turns the user invulnerable and increases the caster's threat level. When the ability ends, damage received is reflected to all enemies in range, then grants Wukong an armor bonus from the received damage.
- Celestial Twin also gains increased threat level under Defy.
Mods[]
The following mods will increase threat level:
- Guardian Derision: Increases threat level when blocking.
Actions[]
The following actions will increase one's threat level:
Items[]
The following item has an increased threat level:
- Deployed Pherliac Pod has an increased threat level against the Infested, including Corrupted Ancients.
Specters[]
- The Shield Osprey Specter has a high threat level, causing enemies to attack it more likely than players or objectives.
Other[]
- The Xiphos Turret has a low threat level, less likely to be fired upon if other allies are nearby.
- Djinn's Fatal Attraction increases its own threat level significantly, causing enemies to lock on (and sometimes fire on it, which is a bug) for the duration.
Trivia[]
- Prior to an update around Update 10.0 (2013-09-13), Rhino's Iron Skin increased the caster's threat level.
