Rad Child (Fallout: New Vegas)

Rad Child is a Fallout: New Vegas, Fallout Tactics and J.E. Sawyer's Fallout Role-Playing Game perk and Fallout: Brotherhood of Steel skill (skills in this game work like perks do in other Fallout games).

You do not take immediate damage from radiation. In fact you gain extra healing while being exposed to it! However, radiation continues to build up in your system as normal.

Fallout: New Vegas
Healing bonuses only apply from different levels of radiation:
 * Minor Radiation Poisoning - HP +2 every second
 * Advanced Radiation Poisoning - HP +4 every second
 * Critical radiation poisoning - HP +6 every second
 * Deadly radiation poisoning - HP +8 every second

You will still die when you reach 1000 rads.

This perk is often overlooked due to the high requirements (70 Survival and radiation sickness), but the effect is very potent, especially for melee and unarmed character builds. Consider trying it with the first level of radiation (-1 Endurance). If your radiation level climbs too high, you can visit a doctor or take RadAway. Alternatively with such a high survival, rad lowering consumables such as cave fungus may be effective as well.

The greatest combat benefit for this perk is provided if you are able to keep your character consistently at deadly or critical RAD poisoning. There is a significant SPECIAL penalty (-3 END, -2 AGI, -1 STR for critical radiation poisoning), (-3 END, -2 AGI, -2 STR for deadly radiation poisoning), but the +6 HP/sec or +8 HP/sec is 60-80 times more effective than the very expensive Monocyte Breeder implant or Solar Powered perk, which only provides 1 HP every 10 seconds (+0.1 HP/sec). Keep plenty of RadAway on hand and try to stay near the edge of critical and deadly radiation poisoning.

following a lengthy melee fight using Rad Child, you are likely to find yourself with multiple crippled limbs and full health, so keep in mind you will still need doctor's bags to heal limb damage and crippled limbs, particularly on Hardcore mode. Human flesh is also an option with this perk due to providing a large reduction of hunger and providing high rads in the absence of a nearby source.

If you plan on using it with higher levels of radiation, be very careful when fighting enemies that irradiate you, such as glowing ones and golden geckos, as they can quickly push you into the final level of radiation: instant death.

Like the monocyte breeder this perk allows you to recover while waiting/sleeping, effectively removing the need for sleep as waiting one game hour will restore from 120 to 480 hp depending on level of sickness.

Fallout: Brotherhood of Steel
With this skill, Cain restores HP whenever he takes radiation damage.