With each rank of this perk, you gain a permanent +3 to your Damage Threshold.
This perk is ideal for players using light armor. It is also noted that the perks Travel Light, and Light Touch go well with this perk for those who are using light armor.
Fallout 4[]
“If nothing else, you can take a beating! Assuming you'll be dealing with more than simple foul language hurled in your direction, gaining a permanent bolster to your Damage Resistance is just like having a thick skin of armor. A fantastic way to spend a Perk Point or five.”— Fallout 4 Vault Dweller's Survival Guide description
In each respective game, the chest emblem has a number signifying a vault. Fallout and Fallout 2 each have a 13 on them, representing Vault 13. In Fallout 3, the chest emblem has a 101, representing Vault 101. In Fallout New Vegas it is a 21, representing Vault 21. And in Fallout 4, the Vault Boy's chest emblem has a 111 on it, signifying Vault 111.
Behind the scenes[]
The image for this perk is a reference to Superman, especially in Fallout, Fallout 2 and Fallout Tactics since the Vault Boy also has the Superman hairstyle.