I feel the little information blizzard has about faction change are too vague
I’ve seen the reputation equivalents for both factions on blizz’s website, but what about all the other reputations that aren’t listed?
Heres link to the reputations that I have done on my main: https://imgur.com/a/rKN6WXR
Specifically, which reputations do I lose (have to redo)? I’ve heard you lose some, other say you lose nothing. Some say you lose EVERYTHING related to argent tournament - is this true?
Other than that, what else do I lose / have to redo? I know the faction related story / quests will have to be redone.
The information from the Support Article is a callout for reputations what would be affected by the faction change. The list is showing how the reputations get mirrored to the new Faction.
Everything else is considers faction neutral so your reputation doesn’t change with them unless otherwise called out.
You don’t really lose all “progress” related to the Argent Tournament. You just haven’t gained it. This is because the vendors aren’t unlocked through rep gains, they’re unlocked because you’ve gone through the daily grind of becoming a Valiant > Champion etc for each city. You’re not going to find that you have unlocked the Darnassus City vendor, by virtue of unlocking the Undercity vendor, for example.
You don’t lose pets / mounts that you have purchased and applied to your account. Once you’ve got them you’ve got them. I believe some but not all have faction / class restrictions in place for use.
I don’t know what would happen to progress if you Faction changed twice. Would the Horde vendors still be unlocked if you went Horde > Alliance > Horde? No idea. I’d get all the stuff before you did so, or seek further information.
EDIT: Just double-checked - the City mount rewards are actually double faction - you don’t need to earn them again on the opposite faction city.
