Child at Heart (Fallout 3)

Child at Heart is a Fallout 3 perk and a cut perk in Fallout: New Vegas.

Fallout 3
The Child at Heart perk greatly improves your interactions with children, some adults and a robot, usually in the form of unique dialogue choices.

Little Lamplight
The Child at Heart perk is particularly useful in Little Lamplight, where a lot of children are present.
 * Mayor MacCready will allow access to the town. This is arguably its biggest plus, since it allows either skipping Rescue from Paradise entirely or completing it later.
 * Mayor MacCready will also give permission for trading Buffout and strange meat for cave fungus.
 * Biwwy will give the Wazer Wifle for free (or "fwee").
 * Eclair will trade (1 cave fungus for around 50 caps).
 * Knick Knack will trade his goods at a discount. He can also assist in The Replicated Man, telling about Pinkerton.
 * Zip can be convinced not to open fire (not that he can, since he is not allowed to have his gun with him in town).

Other Areas

 * Maggie in Megaton will tell the combination to Billy Creel's safe.
 * Bryan Wilks, in or near Grayditch, will give the key to his father's weapon and ammo stash.
 * Rachael, Ralph and Flower will allow entering The Republic of Dave.
 * James Hargrave in Rivet City can steal ammo.
 * Derek Pacion in Canterbury Commons will tell the weaknesses of the AntAgonizer and the Mechanist during the quest The Superhuman Gambit.
 * Dean Dewey in Roosevelt Academy will ask for a hallpass once he is activated at a terminal. He can be convinced about having forgotten a pass with this perk and prevent his hostility.
 * Penny in Paradise Falls can be convinced to leave Rory McLaren behind during Rescue from Paradise.
 * The Mechanist can be convinced to stop trying to be a hero when reminding him that his actions are putting Derek Pacion in danger.
 * Sapling Yew in Oasis will tell about Harold's fear (fear of fire - burning to death) and will give his charm upon completion of the quest.
 * Machete in Canterbury Commons will acknowledge that she was on her way to Big Town but decided she would rather explore and ended up where she is now.
 * Croatoa in Point Lookout can give the fertilizer shovel.
 * Kenny in Point Lookout will allow storing one's gear and sleep in his cave without having to search for and return his Kenny-bear.
 * Midea in The Pitt will disclose Wernher's location during Free Labor.
 * Sally on Mothership Zeta can escort to a hidden stash in the engineering core through an otherwise impassable forcefield.

Fallout: New Vegas
This perk exists as unimplemented content in Fallout: New Vegas and there are a few uses for it hidden in the game's code, but because there are very few children in the Mojave wasteland it was left out.

Bitter Springs refugees
Regardless of which greeting is heard, player receives the Barnabas bear.

Lindsay
Lindsay is the Mini Boomer at Nellis who is missing her teddy bear, Mr. Cuddles.

Max
Max is the boy in Freeside who chases his friend around with Euclid's C-Finder.

Melody
Melody is the slave girl at the Fort.

Dusza Dziecka Вечное дитя Kind im Herzen