How do you make the Great Khans join the NCR?

[DeadByDefault]

Dear fellow wanderers of the wasteland,

For some unbeknownst reason, I simply cannot make the Great Khans join the NCR. Regis says that he would be willing to join the NCR if he were in charge, but he cannot because Papa Khan is in charge. If I kill Papa Khan, the quest 'Oh My Papa' simply fails, and Regis has no further dialogue options. If I complete 'Oh my Papa', the same applies, regardless of whether Papa -- or Karl, for that matter -- lives or dies.
I have not been able to find a conclusive answer to this question on the internet.

Thank you very much for your time.

Regards,

DeadByDefault

[ronr42]

Here's the wiki link for Oh My Papa. You need to show Regis Karls journal or the slave ledger to have the Khans join the NCR. You also need to convince Melissa, Jack and/or Diane to join by gaining their trust. http://fallout.wikia.com/wiki/Oh_My_Papa

[Curious Incubus]

The Great Khans won't join the NCR, and Regis isn't interested in becoming leader of the Khans. Papa Khan is a perfectly capable leader, but is completely biased against the NCR. You just need to convince the Khans not to join the Legion.

[Vassago Rain]

The don't join the NCR, they simply drop their grudges.

You can then convince papa to do a suicide charge on Caesar, or abandon Vegas for new lands. It takes huge speech or a key item to do this.

If you murder a lot of NCR named characters, papa will get super impressed, and declare that you'll be the next khan of khan should be die. Then simply have him stealth killed, and order the khans to do whatever you want them to.