Ghost Town Gunfight is a quest within Goodsprings, available once you complete Back in the Saddle.
When you enter the Prospector Saloon, you will see an argument between Powder Ganger Joe Cobb and the owner. When you talk with her, she will mention that Joe Cobb was looking for Ringo, who is located in the nearby gas station.
If you want to help Ringo, make sure you aren't wearing a hostile outfit (or keep at least neutral reputation with his group) and offer to take care of Joe Cobb. However, he states the best way to take care of him is to take out the local gang. He suggests speaking with Sunny Smiles to get assistance. Sunny will give information on how to enlist additional assistance:
- Trudy can be enlisted, provided you can convince her about a plan. (Speech 25 or Sneak 25)
- Chet can be convinced to open the store's stock. (Barter 25, or 1000 caps)
- Easy Pete's dynamite can be procured, but only if you know about explosives. The dynamite sticks will be provided once the attack starts. (Explosives 25)
- Doc Mitchell can give additional stimpacks. If you know enough about medicine (30 skill points), you will also receive 2 doctor bags.
When you are ready, return to Ringo and speak with him. When you're ready, Sunny will enter and say the attack is about to start. Follow her back to the saloon and store. From here, you can join formation with the militia, or take a flanking position in front of the store but behind a rock. Of the six Powder Gangers, Joe Cobb is wearing armor, which makes him resistant to damage if you are only using lower quality weapons. There will also be one or two Powder Gangers with varmint rifles, which may inflict the most damage.
When the attack is wiped out, Ringo or Sunny will approach to debrief you on the quest. You will also gain infamy with the Power Gangers, and they are likely to attack if they see you in the future.
Run Goodsprings Run
If you prefer turning against Goodsprings, speak with Joe Cobb. He will loiter near Trudy's house, a bit to southwest. If you already spoke with Ringo, he won't trust you.
To side with him, you need to kill Ringo, and return to Joe Cobb about the news of his death. Joe will now start plans to take over Goodsprings, and will ask you to collect supplies from Doc Mitchell or Chet.
Once collected, head to Joe and get him to start the attack.