Fire Shield

"Retaliate on taking heavy damage."— Pickup Text

The Fire Shield is a common utility item in Risk of Rain and deals physical damage.^[1] Retaliate on taking heavy damage

Damage dealt is 200% of your base damage. Upon activation, an explosion occurs which knocks back enemies while also hurting them.

Will not activate if the damage is absorbed by Guardian's Heart.

Tactics

Fire Shield can be activated by the Lost Doll, without risking being struck by attacks from multiple enemies.

The explosion damage of Fire Shield is treated as an on hit, making on hit and on hit chance items able to proc off of it. Examples are:

Brilliant Behemoth: Creates an additional explosion around you. The explosions made are the total number of enemies that are hit.
Leeching Seed: Delayed healing for 1+nº of enemies hit by the explosion.
Ukulele
Prison Shackles
Permafrost
Boxing Gloves
AtG Missile Mk. 1: The missile damage is amplified by Fire Shield, dealing twice as much damage.
- While the Mk. I version missile damage is amplified, AtG Missile Mk. 2 doesn't.

...and all the other on hit and on hit chance items.