The Nuka-Cola Challenge

 is a Fallout 3 side quest connected with the Nuka-Cola soft drink. It is also an Xbox 360, PS3 and PC achievement.

To start this quest, find Sierra Petrovita at Girdershade, which is located west of Jocko's Pop & Gas Stop and SW of Smith Casey's Garage.

Upon finding Sierra Petrovita, she offers you to take the "Nuka-Cola tour," which consists of viewing the large number of Nuka-Cola collectibles she owns. If you agree to take the tour, she will show the player around her home, discuss various Nuka-Cola facts and talk about some of the items in the room. After the tour, she gives the player an Ice Cold Nuka-Cola.

She then asks the player to collect Nuka-Cola Quantums and says she will pay 40 caps for each bottle. Once she has been given 30 bottles, enough to fill her Nuka-Cola Vending Machine, she provides a Schematics - Nuka Grenade.

After exiting her house, Ronald Laren will ask the player to instead give him the Nuka-Cola Quantums, as he hopes that giving them to Sierra will improve his chances of "plowing her bean field." He offers to pay the same price for the Quantums, though a successful Speech check will cause him to double the payment. You also have the option if you have the Black Widow perk to offer a threesome in exchange for him finding the bottles, causing him to eagerly run off to his death. His body can be found inside the main entrance of the Nuka-Cola Plant.

Note
Optional Quest Receive shipping manifest: This Optional Quest will appear when going in the Nuka-Cola Plant. You can get the code from Milo the Robot Foreman by either winning a speech challenge, killing him, obtaining an employee badge, or by using a dialogue choice obtained through the Robotics Expert perk. The code is used in the computer terminal in the room where Milo is found. After using the code, select the option to retrieve the shipping manifest.

Bottle locations

 * See Nuka-Cola Quantum bottle locations.

Rewards
Sierra pays you for the Nuka-Cola Quantums (40 caps each). Once you give her enough to fill her Nuka-Cola Vending Machine, she gives you the Schematics - Nuka Grenade, and you get +300 karma. In the future, she will also make you a Mississippi Quantum Pie if you bring her the ingredients.

Giving the bottles to Ronald Laren results in a loss of karma (150?) and double the caps (80 caps each) if you succeed in the Speech check, otherwise you get 40. Once the quest is complete (if you gave him 30), he goes to Sierra's house straight away and starts making moves — only to have Sierra completely misunderstand his advances.

For maximum money and good karma, it is possible to give 29 bottles to Ronald, and 30 to Sierra. However, a total of 59 bottles is a difficult achievement and will make it very hard to make any Nuka Grenades or Mississippi Quantum Pies, as Nuka-Cola Quantums are semi-rare.

Theft
If you are of the kleptomaniac type, you can steal all of Sierra's Nuka-Cola. There are about 71(65 found around the room, 5 ice cold in the fridge,and 1 from the tour) bottles in total, you will lose about 350 Karma doing so. She doesn't seem too depressed if her prize collection suddenly disappears (provided she doesn't catch you). If she does catch you, she tends to flee. If followers are brought along, they will kill her, so be forewarned.

As there is no key to the Pristine Nuka-Cola Machine, the only way to open it is to use the "unlock" console command on the Pristine Nuka-Cola Machine in the computer version of the game. If this is done, the 30 Quantums may be stolen back, although the "player.additem" console command is a much more efficient means of cheating.

Trivia

 * The name of this quest is a reference to "The Pepsi Challenge," a taste-test marketing promotion run by PepsiCo since 1975.


 * Despite the difficulty of the quest, all Three Dog will say about it on the radio once you've finished the quest is "It seems the Vault Dweller's done collecting soda....talk about your slow news days".


 * If Sierra is killed, and Ronald is spoken to, a Speech check can be passed in which the player blames the Nuka-Cola Corporation for her death. He'll assume it because the Nuka-Cola machine he got had a label saying; "Warning if you tamper with this unit you'll have to answer to the Nuka-Cola Corporation". This dialog is likely a reference to a scene from the film Dr. Strangelove involving tampering with a Coca-Cola machine.

Bugs

 * If the player starts the quest and immediately gives Sierra all 30 bottles, she may only give the player 40 caps in total, rather than 1200 caps as she should. The Nuka-Grenade Schematics may also not be given. Despite this, it will still count as completion of the quest. Leaving and getting a bottle before doing this, or even dropping a bottle and picking it back up can remedy this quirk.


 * Similarily, Ronald may not pay for the Quantums if they are given to him.


 * If this quest is completed before the unmarked quest Just for the Taste of It, Goalie Ledoux will not appear, making it impossible to complete.


 * Sometimes, Sierra Petrovita will run around her home in "fleeing" mode for a random period of time. In some cases, she won't come out, making it impossible to talk to her. Reloading a save will not always fix this. It appears to happen randomly, but known causes include the player killing an NPC that she likes (Ronald) or having a hostile NPC follow the player into her house. Using a pip-boy while she is fleeing, will cause her to stop fleeing (tested on the xbox 360 version only).


 * Random enemies may spawn in Sierra's house. Among the guests include Sentry Bots, Deathclaws, Giant Radscorpions, and even Enclave troops. If this happens, if they are not killed quickly, Sierra will be killed, failing the quest.


 * The quest never updates after you get the manifest from the Nuka-Cola Plant Factory Floor.


 * If Ronald is sent to the Nuka-Cola Plant with the Black Widow perk, and the player immediately fast-travels there and kills all the security Protectrons on the first floor, he won't die. He'll appear inside the plant later, alive and well, standing near the front door.