Guilds
Clans/Reputation
Instead of Aurors vs Deatheaters we have Peace vs Chaos, both of which are vampire schools/arts of magic battling each other, wizards and witches join their cause and gain fame, this is over one numeric scale, if you gain peace, you lose chaos and vice versa.
There are reputation ranks, each rank has maximum reputation you can earn, upon reaching the maximum you have to do a rank up quest to continue earning more reputation. However, once a week at Sunday your reputation will decay and you will lose 10% of it.
A rank up is achieved by doing a rank up quest given by a vampire lord found in one of the clan HQs.
What can we do with reputation?
Reputation can be used to buy certain items from a shop found in an HQ's meeting room as well as reset your k/d from a respect NPC, also found in an HQ's meeting room.
Aside from that, this factor helps determine your guild's score.
You can gain reputation by killing chaos/peace vampires or killing players famous of supporting the opposite clan as well as doing weekly/daily quests that reward reputation.
Guilds
Guilds are a player-made group, they can be made regardless of level or reputation of any member, there are no restrictions except member limit, at time of writing a guild capacity starts at 2 and can be upgraded to 5, costs 5 artifacts and 500,000 gold per upgrade.
(*HQ vaults were made with 5 rooms and can be used as a minor guild HQ)
You can start your own guild by talking to Guildmaster and paying 1,500,000 gold and 15 artifacts, you can also buy guild upgrades from him, right now it's just capacity upgrade but might have more in the future.
The guild panel can be accessed via the sign on colored pillars at the bank offering several common guild functions such as MOTD, member list, ranks, invite, promote, demote, quit/remove member, all that is pretty straight forward. I should note that sending an invite costs 200,000 gold regardless of whether they accept or decline the invite.
A guild's score is determined by it's members total sum reputation and average matchmaking skill rating, this gives an accurate tell of how strong and active a guild is.
You can invite whomever you want however since they fill a member slot as well as impact your score you may wish to only invite people who carry their own weight and align themselves with the same clan as you.
Major Guilds
A guild is normally considered a minor guild however, during Sunday right before reputation decay there is a major guild election, if you are the top guild in your clan you will become a major guild which grants you access to peace/chaos clan HQs and perhaps more benefits at the future.
The election occurs only at Sunday, once a week, you can not steal another guild's major status during the week.
This summarizes everything you need to know.
The heavy costs ensures that guilds will be led by reputable players and prevent spam. It's recommended to work as a guild to the pay the costs rather than pay everything yourselves, it is about working together after all.