Immovable
Signature
Once per fight: cannot drop below 1 HP; heals on trigger.
Rolls between 5% and 20%, scaling with the gear score of the item carrying it.
Forge mods that grant it
Spending one of these puts the perk on your gear instead of waiting for a roll.
Rolls on
Shield
A drop or a craft of these types can roll this perk into one of its slots.