Your brain has been replaced with advanced technologies: Your head can no longer be crippled and is resistant to chem addiction (+25% resistance) and shock from bodily damage (+5% Damage Threshold, minimum +1).”— Fallout: New Vegas description
In the initial dialogue with Doctor Klein as part of the quest Welcome to the Big Empty, you find out that your brain, heart, and spine have been removed and replaced. This perk represents the replacement of your brain. While you technically have these perks from the start of the add-on, they are unlocked in the course of the conversation.
Your head cannot be crippled, you gain 5% DT (minimum 1) and a 25% resistance to chem addictions.
- Compared to the Big Brained perk, you gain an additional +15% chem addiction resistance at the cost of -5% DT.
- The DT added by this perk and Big Brained does not work correctly. See the Big Brained talk page. A fix for the PC version is available here.
- Synergizes well with the perk Chem Resistant and Old World Gourmet Dead Money for 71.875% chem addiction resistance.
- However, it synergizes poorly with Eye for Eye, as it reduces the total number of limbs that can be crippled.
- Brainless shares the same Vault boy image as Big Brained.