Introduction

EPGP is based on the concept of Effort Points and Gear Points. Effort Points quantify the effort each member put towards the (common) guild goals and Gear Points quantify what each member got back in return. Loot priority is computed as the quotient of the two; priority (PR) is equal to EP/GP.

In a sense EPGP is like zero sum, but without all the need to rebalance the system, or impose taxes to give points for other effort put into the guild. Zero sum awards GP/N points to each player for each item dropped (GP the value of the item and N the number of players in the raid) so that the sum of all points for the members of the guild is zero. EPGP on the other hand is by definition self balanced since priority (and hence chance to receive loot) is directly proportional to the effort you put and inversely proportional to the rewards you got. It is also much more flexible than zero sum since it doesn't require a specific balance point (sum to be equal to zero for example). As such points can be awarded for almost anything without any taxation or over complicating the system (see below). Also another problem with zero sum is the random value of each boss. A boss kill is a boss kill and the effort to kill it is the same no matter if it happened to drop 1 or 2 epics. With zero sum since the amount of effort points the members get is proportional to the loot dropped which is definitely not representing fairly the effort each member puts in the guild.

EP can be awarded for a variety of activities:

• Being on time for raids
• Killing bosses
• Wiping on new boss tries
• Being present until the end of raid
  

GP points are imposed for receiving loot in a raid.:

Another twist in EPGP, that makes it different than other loot systems is the fact that EP and GP decay over time. The decay can be set by the guild master (it can also be disabled if it is set to zero). With a decay of N%, after each raid the guild participates in, each member gets her EP and GP reduced by N%. This eliminates EP (DKP) hoarding.

Because of the fact that EP decays over time, we can use a simple metric to estimate attendance: Min EPs. Given a value for Min EPs we choose to give PR = 0 to those that have less than Min EPs. As an example, assume a guild where about 500 EPs are awarded per member per raid and a Decay of 10%. If Min EPs is set to 1300 then a member needs to be in at least the last 3 raids to be eligible for loot (500+450+405), or the last 4 raids before the last one 450+405+365+329. This is arguably a better measure than attendance, as attendance is a somewhat loose criterion: if a member came to a raid for 1 hour only and the rest were in it for 4, do they all count as the attended the raid? Since EP measures the effort of each member, having a Min EP puts the cut-off at an effort point which will work both for new members and old members. An old member that is idle for a long time will loose EPs gradually so she might get lower than Min EPs which makes her ineligible for loot. A new member starts with EP equal to zero so he needs to attend some raids in order to get his EP above Min EP to be eligible for loot.

GP Values

When designing the GP formula the following requirements were set:

• Total GP for each class/spec should be ideally the same.
• Items of a whole new and better tier should be increasingly more expensive. A factor of two was chosen for each tier.
• Each item should cost as much GP as it's power according to the class/spec that uses it.

While the relative item budget between slots is widely known (Item Level) there are class/spec combinations for which an item is more beneficial than others. These depend on how the class/spec is designed and what kind of stats it prefers or primarily uses. The cases we are more interested in are:

• Shields: A tanking shield is used by shield capable tanking classes. In that case a tank is interested in both the white stats and the green stats of an item. A healing shield, which is used by shield capable healers, is used primarily, if not exlusively, for its green stats. This should be taken into account by the GP formula.
• Weapons: Melee classes use both the green and white stats of a weapon. Both the dps of the weapon and the stats on it are useful. The white stats of a weapon are not at all useful for a hunter. This also needs to be taken into consideration. Note: Casters get the white dps of a weapon and make it into spell power through some fixed formulas, so spell power on weapons is considered a white stat.
• Ranged weapons: Hunters use ranged weapons for both their white stats and the green stats. This is not true for melee classes which use these items only for their green stats.
• Off-hand weapons: These weapons are used by dual wielding classes/specs and because of the off hand weapons 50% damage modifier, the white stats on these items are severely less important. Obviously GP needs to account for this as well.

With the above in mind the following formula was devised:

GP = 0.483 x 2 ^{ilvl/26 + (rarity - 4)} x slot mod

Rarity is given by this table:

Slot modifiers depend on the slot each item can be equipped. In addition to that, the forementioned differences between the use of certain weapons/offhands is taken into consideration. This means some items have two possible GP values which depending on who uses them and how they are used.

The basic values slot modifiers for each slot are:

Under certain circumstances a different modifier is used. These are:

• 2H Weapon:
  • If it is going to be used as an offhand (TG warriors for example) the modifier becomes 1 (down from 2)
  • If it is going to be used by a hunter the modifier becomes 1 (down from 2)
• 1H Weapon:
  • If it is going to be used by a hunter the modifier becomes 0.5 (down from 1.5)
  • If it is going to be used by a tank for tanking purposes the modifier becomes 0.5 (down from 1.5)
  • If it is going to be used as an off-hand the modifier becomes 0.5 (down from 1.5)
• Shield:
  • If it is going to be used by a tank for tanking purposes the modifier becomes 1.5 (up from 0.5)
• Ranged:
  • If it is going to be used by a hunter the modifier becomes 1.5 (up from 0.5)

This gives more or less equal GP value for MH + OH + Ranged slots for all classes:

As shown by the table most classes end up with the same totals, with the exception of TG warriors that are charged a little bit extra.

Examples

With the theory out of the way lets see some examples of items and how different components of the equation affect GP.

A tier of gear difference. Both items are epic 2H weapons, but they have a whole tier of loot difference:

• Betrayer of Humanity 399 GP
• Colossal Skull-Clad Cleaver 199 GP

As expected the higher tier item is 2x as much GP as the lower tier one. Now lets see two items of the same ilvl, same slot but different rarity:

• Colossal Skull-Clad Cleaver 199 GP
• Mojo Masked Crusher 99 GP

Again as expected the two items have a 2x GP difference between the two weapons because the one is epic and the other one is rare. With the rarity and tiers out of the equation lets look at the whole tier 7.10 set for the warrior class:

• Heroes' Dreadnaught Helmet 99 GP
• Heroes' Dreadnaught Battleplate 99 GP
• Heroes' Dreadnaught Legplates 99 GP
• Heroes' Dreadnaught Shoulderplates 74 GP
• Heroes' Dreadnaught Gauntlets 74 GP

As you can see both shoulders and hands are 0.75x of the cost of the head, chest and leg items since their relative power is 0.75x as much.

Problems/Solutions

This problem is non-existent in EPGP because of the use of the EP and GP decay. Only temporal EP and GP are accounted. So the latest you "use" your PR lead the least amount of benefit you get out of it. And the earliest you take an item, the faster its value will decay.

New members vs Veterans

Because of the decay, new members become equal under the system much faster. EPs decay over time so with a 10% decay in about 15 raids a veteran has about the same EP as a new member (if they both attended the same raids). The only barrier to entry for new members is reaching Min EPs in order to be eligible for loot.

Members that are geared up vs members that are not

Members that are geared up already will end up with the highest PR possible and will have first priority over a new (and possibly rare) drop. This will satisfy these members. Members that are not geared up already will end up getting loot in most raids which will keep their priority low. So they will still gear up but they will not threaten members that wait for a special piece to drop in order to get their satisfaction as well.

Complexity

Unlike Zero Sum with taxation, which is very similar, there is no need to rebalance when members join/leave guild, and no changes in tax/decay because of more tries on new content. The reduced complexity of the system allows more people to understand it, which keeps the queries to the guild master low and member satisfaction up.

Hard to assign item values and boss kill/tries values

Because effort points are decoupled from effort points it is easier to assign "good" values for each category. Guild Masters/Officers can focus on balancing different boss kill/tries, materials farming rewards separately from item values. If you notice in the above example nothing would change if each raid was awarding 987 EP and each piece was worth 123 points. Balancing rewards and items is extremely hard; balancing them in isolation is quite simpler.

Randomness on Boss Value in Zero Sum

Zero Sum's major flaw is that for the same encounter, you might end up getting more or less points, depending on the loot (which is random). This introduces a major cause of unfairness to the system, since the same boss, which requires the same effort, is worth more in some runs and less in others. In EPGP each boss awards the same EP every time, adding to the fairness of the system.