After completing one of the first quests, Fallout: New Vegas players often become vilified by the Powder Gangers. How do you not be vilified by Powder Gangers?
You can not be vilified by Powder Gangers by ignoring the “Ghost Town Gunfight” quest. Either ignoring the quest to help Goodsprings, or siding against the town, will not vilify you against the Powder Gangers.
Becoming vilified will prevent you from accessing Powder Ganger side quests in the NCR Correctional Facility.
Not becoming vilified by Powder Gangers
After meeting Sunny Smiles, she’ll encourage you to visit the saloon in Goodsprings. Once entered, the player witnesses Joe Cobb, a member of the Powder Gangers, arguing with Trudy, the bartender.
Cobb asks where Ringo, a trader, is hiding in Goodsprings. At this point, the player can decide to side with Goodsprings and push the Powder Gangers out of town, or side with the gang and take over Goodsprings.
Most new players side with Goodsprings. One of the first quests in the game, many players avoid siding with the Powder Gangers out of fear of “ruining” a good-karma playthrough. Regardless, pushing the Powder Gangers out of town will cause your reputation to become “Vilified.”
Once hated enough, members of the Powder Gangers will attack you on sight. This is similar to when you’re vilified by the NCR. The gang operates in a very small area, so this isn’t a huge deal. However, vilification will lock you out of a few Powder Ganger side quests at the NCR Correctional Facility.
In order to avoid this, simply ignore the “Ghost Town Gunfight” quest. This will allow you to preserve neutral karma with both Goodsprings and the Powder Gangers.
If you want to side with Goodsprings, your best bet is to ignore the quest at first. Seek out the NCR Correctional Facility, cash in on faction-quest XP that’s available to you there, then return to Goodsprings and help them.
Once you’ve cashed in the side quests at the Correctional Facility, there’s not much more benefit you can gain from the Powder Gangers. They’ll fire at you on sight once vilified, but they only roam small areas of the map.
So that’s the answer. You can not be vilified by the Powder Gangers by ignoring the “Ghost Town Gunfight” quest.