EPGP stands for: Effort Points, Gear Points
For every killed boss, you get a set amount of effort points, e.g. +10 EP. For every received item, you get a certain amount of gear points, e.g. +80 GP.
EP have a positive effect. The more bosses you kill, the higher your DKP score will be. GP have a negative effect. The more items you get, the harder it will be to receive more loot.
Your DKP score is calculated like this: EP divided by GP = Score. On your first run, you start with 0 EP and 200 GP (Base-GP).
Example:
- 1st Raid: +80 EP received, no item dropped: 80 / 200 = 0.4 Score
- 2nd Raid: +80 EP received, you got tier gloves for +120 GP: 160 / 320 = 0.5 Score
- 3rd Raid: +80 EP received, no item dropped: 240 / 320 = 0.75 Score
Points are updated instantly after every boss/item. While distributing loot, the addon posts the scores of all interested members to the raid chat in descending order. Usually, the bidder with the highest score gets the item.
Exceptions:
- Some items may be prioritized (e.g. tanks first)
- If the highest bidder passes on their own
Of course, the whole idea behind the system is to spread items evenly among all raid members. Effort should be rewarded. Different prices for items of different qualities also help minimize distortions.
Example: Instead of 1 best in slot item for 400GP, you could also choose to take 5 mediocre items for 80GP each.
Basically, the system described above allows two strategies:
- Save points by passing on most items. Get expansive and highly desirable items first.
- Get useful items as they drop, but wait longer for highly desirable items due to a slightly lower score.
The first strategy is seen as kind of selfish, because many items would have to be disenchanted if everybody behaved this way. It is also bad for the raid if too many players run around for weeks with bad gear just to save points for later.
Some classes will probably tend towards the first strategy (e.g. off-warriors because of weapons). But most other classes will choose the second strategy, because many normal items that drop are still very good, some of which only their class can wear and where everybody within that class will end up with a similar score. So, having a slightly lower score does not necessarily have to be a bad thing, because it also means you have already benefitted a lot from dropped items which will also help you score better in DPS meters.
New members are treated exactly the same as everybody else. They do not have a disadvantage due to missing EP because they also do not have any GP. Existing raid members may have a lot of EP but probably also a lot of GP, so it balances out.
But new members with bad gear are practically forced to choose the second strategy. Nobody would understand it if they ran around with blue gear just to save points. On the positive side, this means they will be equipped very quickly with normal items that most other players already have, but very good and expensive items become practically unreachable.
The situation changes when the raid goes on to the next raid content, because everybody starts again with a new account and zero points. New members with very good gear (from other raids) are not affected by this and may choose freely between the two strategies. The aspects mentioned here are probably present in all systems, i.e. no sane raid would simply hand over a top item to a new raid member.