Fragile Strength is a Charm in Hollow Knight. It increases Nail damage by 50%.[Note 1]
Usefulness
Fragile Strength does not affect damage from Nail Arts or the Sharp Shadow, Dreamshield, and Thorns of Agony Charms.
It is an extremely powerful Charm. It permanently provides a similar benefit to Fury of the Fallen without needing to be at one Mask, costing only one more Notch. The combination of both Fury of the Fallen and Fragile Strength provides a ~170.6% damage increase when the Knight is at one Mask.[Note 2]
The downside is that once broken, Leg Eater only repairs it for a price. In the late-game, the cost may not be much of an issue, but the trip to Leg Eater might be. Dreamgate can be used to reach Leg Eater more easily.
This Charm is quite potent, although it breaks upon death. One way to make use of the Charm is to only use it in situations where death is unlikely, such as exploration, or in tandem with survivability-increasing Charms, while also avoiding its use in boss battles, except for Dream Boss battles and 
Godhome battles (as the Charm does not break when dying to these bosses).
Lastly, its drawback is negated in Steel Soul runs since the run is over upon death anyway, making Fragile Strength one of the most powerful and useful Charms in a Steel Soul run.
How to Acquire
Purchased from Leg Eater in the Fungal Wastes for 
600. Wearing the Defender's Crest Charm causes Leg Eater to lower the cost to 480.
- Shop description:
- You're weak, aren't you? You should give me Geo. If you do, I'll give you this charm I made. It will make you stronger. Your enemies, and everyone else, will fear you at last...
When broken, Leg Eater can repair it for 350, or, while wearing the Defender's Crest, for 280.
- Shop description when broken:
- It's broken now, and its power is sleeping. Very sad! Give me Geo, and I'll fix it.
The Grimm Troupe ContentOnce the Grimm Troupe has been summoned, Divine becomes accessible in Dirtmouth. To get the unbreakable version of Fragile Strength, it must be equipped before listening to her, then it must be given to her when prompted. She eats the Charm, then asks for 15000. Once the Geo is paid, she gives the unbreakable version of Fragile Strength, Unbreakable Strength.
Charm Combo Tips
 Fury of the Fallen |
Stacks with Fury of the Fallen, providing a ~170.6% damage increase at one Mask.[Note 2] |
 Grubberfly's Elegy |
Stacks multiplicatively with Fragile Strength, dealing ~77.5% Nail damage per projectile.[Note 3][Note 4] |
 Stalwart Shell |
Especially efficient in combination with Stalwart Shell, allowing the Knight to quickly dispatch a charging enemy without taking extra hits. |
 Quick Slash |
Especially efficient in combination with Quick Slash, allowing the Knight to quickly deal a large amount of damage. |
Notes
- ↑ 1.0 1.1 1.2 The damage is rounded to the nearest integer, or to the nearest even integer if halfway between two. This results in 8/14/20/26/32 damage at Nail upgrades 0/1/2/3/4.
- ↑ 2.0 2.1 First the damage multiplier from Fragile/
Unbreakable Strength (150%) is applied and rounded. Then the damage multiplier from Fury of the Fallen (175%) is applied and rounded, also to the nearest integer. This results in 14/24/35/46/56 damage at Nail upgrades 0/1/2/3/4.
- ↑ First, the damage multiplier from Fragile/ Unbreakable Strength (150%) is applied and rounded. Then the damage multiplier from Grubberfly's Elegy (50%) is applied and rounded, also to the nearest integer. This results in 4/7/10/13/16 damage at Nail upgrades 0/1/2/3/4.
- ↑ With all three Charms, the damage of Grubberfly's Elegy's projectiles is calculated as follows: First the damage multiplier from Fragile/ Unbreakable Strength (150%) is applied and rounded. Then the damage multiplier from Grubberfly's Elegy (50%) is applied and rounded. Finally, the damage multiplier from Fury of the Fallen (150%) is applied and rounded. This results in 6/10/15/20/24 damage at Nail upgrades 0/1/2/3/4.
