Rad Regeneration

Rad Regeneration is a Fallout 3 Perk.
 * Requirements: Exposing yourself to near fatal (600+) radiation for Moira`s The Wasteland Survival Guide quest. This perk (a mutation) is a result of Moira`s experimental radiation treatment.
 * Benefit: When under the effects of "Advanced Radiation Sickness" any cripped limbs will regenerate.

This is a very useful perk if you have the right setup. Get this perk, a set of Power Armor, and become addicted to alcohol. After getting dosed on 400 rads, your limbs (at any damage, it seems) will automatically regenerate. Use this in addition to irradiated water (most usefully found at a Sink) and you can use RadAway instead of StimPaks. The advantage of this is 30 HP typically costs 5 rads, from a water source, and combined with Radaway, can provide more healing than several StimPaks. In addition, your beer addiction will provide you with +1 Strength and +1 Charisma, which helps balance out negatives from Power Armor and provides additional carrying capacity. Beer is worth 3 caps, so buying 20 will add a bit to your weight but also add to your potency.