Lifegiver

Livegiver or Life Giver is a Fallout, Fallout 2, Fallout 3, Fallout Tactics and Lionheart Perk.

Fallout

 * Requirements: Level 12 (11 in Lionheart), EN 4
 * Ranks: 3
 * Benefit: With each level of this Perk, you gain an additional 4 Hit Points. This may not seem like a lot, but every little bit helps.
 * Notes: Although it's not clear from the description, Lifegiver gives you +4 HP when you take it; you could say it works retroactively for the level you just earned.

Fallout 2 and Fallout Tactics

 * Requirements: Level 12, EN 4
 * Ranks: 2
 * Benefit: Everytime your character gains a level, gain an additional four Hit Points for each rank of this Perk. With two ranks of Lifegiver, that’s +8 HP each level!
 * Notes: Although it's not clear from the description, Lifegiver gives you +4 HP when you take it; you could say it works retroactively for the level you just earned.

Fallout 3

 * Requirements: Level 12, EN 6
 * Ranks: 1
 * Benefit: With each level of this Perk, you gain an additional 30 Hit Points.
 * Note: This perk gives you unique dialogue choices when talking with some specific characters, like in the Oasis, Tree Father Birch.
 * In the datafiles, it is listed as being available in 3 levels, but it was changed to 1 level upon release.

Lionheart

 * Requirements: Level 11, EN 4
 * Ranks: 2
 * Benefit: With each level of this Perk, you gain an additional 6 Hit Points.