EPGP stands for Effort Points/Gear Points. It's a system designed to handle loot distribution in a way that is more fair than standard DKP distribution.
The way this works is that EP (Effort Points) is representative of the effort you have put in during raids. Your GP (Gear Points) increase when you win loot, the higher quality loot, the more your GP increases.
When loot drops, you select whether you need it or not. There are several options for you to choose.
It's important to note that the amount of GP you will be credited depends on the option you select.
For Main Spec and Minor Upgrade, you will be credited 100% of the item's worth. For any other option, it is given to you for free. Abuse of this fact (rolling Offspec on gear you need for Main Spec) is not taken lightly and may grant you a loot ban or exclusion from the raid team.
In addition to that, the GP values also depend on the quality of the loot, item level, slot, and stats budget. A ring, for example, is worth less GP than a chestpiece with the same quality and item level, because it has less stats on it.
Also, EPGP is personal and not character-specific. This means that you share EPGP values between all the characters you have in the guild. Earning EP or winning an item on character X will also increase your EP and/or GP on character Y.
Before the first raid in a week, everyone's EP and GP are reduced by 10%. This is to make sure that recent changes to EPGP carry more weight than older ones. So if Joe's EP and GP are 1000 and 500 (respectively) before the first raid, they will be reduced to 900 and 450.
When the group wipes on a boss, they are awarded a small amount of EP in recognition of the effort required. You are awarded 2 points of EP for a wipe on a normal difficulty boss, and 5 EP for every progression wipe on a heroic difficulty boss. This means that once a heroic boss has been killed and is on farm, you will only be granted 2 EP (same as for a normal boss) when wiping on it.
Once a boss has been defeated, every member in the group is awarded 1000 EP. If it's a progression kill on heroic, the amount awarded is instead 1500 EP, which is reduced to 1000 EP once that boss is on farm.
Then, it's on to the loot!
When a boss dies and time comes to distribute its loot, the loot master will distribute each item separately via the addon EPGPLootMaster. Every member in the raid will then get a popup with different buttons to select their loot preference, as shown below.
This window provides you with all the info you need to make your selection. What the different buttons mean was explained above, some other info this popup provides is:
After you have made your selection, you will be competing against other members who chose the same option as you. Most of the time it will be between players who chose Mainspec.
As mentioned before, whoever has the highest PR value is going to win the item. Take this example:
In this case, Seylaina's PR value is roughly (5000 / (600 + 100)) = 7.14, while Shottyy's PR is about (4000 / (450 + 100)) = 7.27. This means that Shottyy wins the loot (higher PR). Even though Seylaina had a higher EP value, Shottyy still won due to having lower GP, which significantly raises the PR in situations like these.
Hopefully this page will have cleared up most of the confusions about the EPGP system, but if you still have some unanswered questions, feel free to contact an officer in-game.
Note that 100 is added to the given GP value before calculating the result.
We don't currently maintain our own database of EPGP data, instead, please refer to our page on EPGPWeb. There you can see the EP, GP, and PR of each guild member, and also recent loot. You can also see your current EP and GP values by looking at your officer note in-game, take the two values and put them in the calculator above to see your PR value. The format in your officer note looks like 1337,500 where 1337 is your EP and 500 is your GP.
In short, EP is Effort Points, GP is Gear Points, and PR is Priority Rating.
Gaining EP increases your PR, gaining GP reduces your PR. PR decides whether or not you win loot, the person with the highest PR wins the item.
The concepts are explained in more detail below.
Killing or wiping on bosses in a guild raid will net you EP. The points are awarded as such:
As your EP increases, your PR will also increase, making you more likely to win loot in the future.
Whenever you win a piece of loot, you get credited with GP. As your GP increases, your PR will decrease. Lower PR means you get less priority at loot. How much GP you are credited depends on the quality and stat values of the item.
Currently, only members with the "EPGP Officer" rank and the Guild Leader are able to manage the EPGP values.
The EPGP wiki is a good place to read up if you want more info on how EPGP works. If you feel this page is lacking in info, feel free to notify an officer in-game and this page will be updated.