Update : it seems that people can get purges even if they are offline, which would mean that it’s total number of online players which is taken in account.
This is really confusing !
From someone on Steam :
Its not is just player numbers we tested that in our server and people were getting purge while offline
EDIT : Very interesting explanations posted by a player on my Reddit thread :
I’ve rented a PS4 server the other day, and my server is a purge focused server with pvp events in an arena I’ve built and raid bases challenges. So all over the map I have small bases for people to raid. With having so many little bases I get all kinds of purges. Here is how the purge settings works.
Purge level: self explanatory, really. I’ve heard people on here and YouTube say that level 3 is the best for the named thralls. I don’t think I agree with that totally. I personally believe the type of purge you’re going to get whether it’s spiders, wolves, cannibals, or apes all depend on your base location.
Purges per day: max is 24(on console at least), and what I found this to mean is exactly that. Your server can have up to 24purges per day. It’s happens one at a time so basically it’s one purge every hour of the day if your server is popular enough.
Minimum number of players online: this is a confusing one, plenty of people think this is server wide, not so, this is clan base. If you have it set to 0 you’ll get offline purges. If you have it set to 1 you’ll get immediately purged when you sign online if your purge meter is full. Which it most likely will be if your trigger meter value is low enough.
Purge update: it’s basically minutes. Lower the number means the purge meter updates more frequently. I have mine set at 3 minutes.
Purge trigger meter value: the lower the number the faster the purge comes. The default is 42k and My server is currently set to 15,000 and I get at minimum 1 purge a day. That’s also someone who has no life and plays for 5-8 hours at a time, I also don’t have anyone in my clan. If you’re a solo player and don’t play a lot you’re probably get the purge I wanna say at least every other day or so. I will say I have logged off when my purge meter just reset after a purge to sign back in about 6 hours later and got immediately purged. So your meter must be going up while you’re offline.
Any other questions about the purge just ask. I’ve been through plenty of them these past server days. The purge is ing awesome so I don’t know why people think it’s broke. It’s their settings are ed up. Now the actual purge can be kind of wonky with attacking for sure but the settings aren’t broke.
So, clan members online and not total players online, it seems…