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This is a hidden perk that works in conjunction with the smart fragmentation grenade. When using a smart fragmentation grenade this perk makes the thrower receive no damage.
This perk is automatically obtained when loading the game with the Nuka-World add-on installed.
Negates damage to thrower of a smart fragmentation grenade.
The help text on the smart fragmentation grenade states that the thrower takes no damage. However the logic involved in the perk actually makes it only apply to the player. In fact if any NPC were to throw one, the player will receive no damage and anyone else in the blast range would.
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