DKP or dragon kill points, is a point system used in online games, specifically MMORPGs such as World of Warcraft and EverQuest II, to distribute items among groups of players. Players receive DKP points from attending events with their guild or clan, and can use these points to "buy" loot (items) that drops at a future date. This system allows more active members to receive more/better rewards, whereas those who contribute less receive less in turn. The DKP system was originally named and developed by the EverQuest guild "Afterlife" in 1999. A massive(ly) multiplayer online role-playing game or MMORPG is a multiplayer computer role-playing game that enables thousands of players to play in an evolving virtual world at the same time over the Internet. ... World of Warcraft (commonly abbreviated as WoW) is a massively multiplayer online role-playing game (MMORPG) developed by Blizzard Entertainment. ... EverQuest II (commonly abbreviated as EQ2), the sequel to EverQuest, is a fantasy massively multiplayer online role-playing game (MMORPG) developed by Sony Online Entertainment (SOE) and shipped on November 8, 2004. ... In computer and video gaming, a clan or guild is a group of players who regularly play together in a particular multiplayer game. ... Looting in a gaming context, specifically in MMOGs, is the process by which a player character obtains items such as in-game currency, spells, equipment or weapons from the corpse of a creature or possibly the corpse of another player in a PVP situation. ...

Why DKP?

Many MMORPGs have high-end items which are randomly generated in small numbers when certain very powerful enemies in the game, or "bosses," are defeated. Typically, these items "drop" in quantities much smaller than the total number of players in the group required to defeat them, so a means of deciding which of the players should receive the items is required. One method is random chance. Some games, such as World of Warcraft, have built-in mechanisms by which players can decide the distribution of items by chance. But many players find this system, though "fair" in the sense that any player in the group has equal probability of receiving the item, unsatisfying. Flag Ship from the video game Gorf In video games, a boss (sometimes called a guardian or master) is a particularly large or difficult computer-controlled character that must be defeated at the end of a segment of a game, whether it be for a level, an episode, or the... World of Warcraft (commonly abbreviated as WoW) is a massively multiplayer online role-playing game (MMORPG) developed by Blizzard Entertainment. ...

For example, with random distribution, it is possible for newer members of the group to receive items that existing members have expended great effort to find. Many players prefer a means to afford to those players that most participate in the activities that generate these items an increased ability to successfully win these items compared to those players who participate less.

Goals of DKP systems

DKP systems are often a balancing act of a number of conflicting goals. Some properties that would be desired in a system:

• Items should be assigned in a way perceived as fair by the participating members.
• Items should be assigned in a way that increases the overall strength of the guild/clan, thus making future encounters easier.
• Established members who have worked hard toward particular items should be able to get those items reliably.
• New members should be able to receive valuable items as an incentive for guild membership.
• Highly valuable items should always be assigned to some guild member; if items are not distributed, the guild as a whole misses an opportunity to strengthen.
• The system should be relatively easy to administer and understand.

Meeting all these goals at once is probably not possible, so individual guilds and clans need to set priorities when designing their particular DKP system.

The other ideas behind these systems are also not universally accepted. Some might say the guild's right to control who gets the loot (regardless of whether it would help the guild or not) is limited to the amount of effort the guild put into making the raid successful. If the leader of a dungeon group has the ability to determine who he can successfully run a dungeon with and do so, then each person is solely responsible for meeting those requirements and equally participating in the guilds success. If such leaders exist, then why should someone join a guild where they fail more often and want to claim greater responsibility for the loot than newer players who come along that could meet all requirements and equally contribute in a current dungeon group run by such a leader?

Basic DKP

DKP is actually not a single system but a number of competing systems that all use the name "DKP." The most basic of these systems is as follows:

• Each time a boss is defeated by the group, or alternatively whenever an item drops, each member of the group receives some number of points. Points may also be awarded for other things deemed valuable by the guild -- for example, based on total number of hours of attendance at raids, showing up on time and staying until the end, or contributing consumable materials (like potions) used by other members on the raid.
• Whenever an item drops which is desired by more than one player in the group, an auction takes place using the points already received. The highest bidder receives the item.

Problems with basic DKP

Basic DKP is both simple and easy-to-understand for players.

There are a few potential weaknesses with a basic DKP system. Firstly inflation, if a system has too many points going in but not enough going out then often established players have a large bank of points that they can afford to buy most of the loot without new players being able to catch up.

The next problem is distorted prices due to class imbalance. If an item is highly desirable for one class and that class is oversubscribed then the price of that item is likely to be very high. This means that collectively that class will have less to spend on items that are useful for all classes. This is supply and demand at work, the net effect is that oversubscribed classes will be worse off than undersubscribed classes.

Additionally, it is vulnerable to a collusion attack. To use collusion to defeat basic DKP, it is necessary to first understand that many items are useful often to one small class of players, such as only Warriors, or only Priests. If, for example, a "Warrior-only" item drops, the warriors could all agree to limit their spending of DKP, such as by assigning it randomly and then bidding the minimum bid, or by placing a ceiling on the price. In this way, all warrior items are relatively undervalued compared to items from other classes. This means that when items useful to multiple classes, including warriors, drop, the warriors will, as a group, have more DKP to spend than those from the other class.

Modifications to basic DKP

One modification attempts to repair the collusion vulnerability in DKP by using a separate set of points for each class that are spent on class-only drops. This greatly mitigates the effects of collusion at the expense of significantly complicating the system and making it harder for many players to understand.

Other changes involve the assignment of points to players under different circumstances than those described for the basic DKP system. For example, points may be awarded for being on time to guild or clan events, or based on time spent on an encounter in the group or raid. In addition, bonus points are often awarded the first time a major encounter is successfully completed by the group to encourage people to be involved in the effort required to allow the group access to this new, higher-power content.

Some systems have procedures for renormalizing the point totals so that established players do not have hugely inflated numbers of points, preventing players who joined later from ever receiving items other than "leftovers." This may involve subtracting a fixed number of points from everybody on a regular basis, or devising systems by which points will decay over time. For example, the guild could decide to subtract from every player the average of the players, or to multiply the total of all players by a constant smaller than 1. These techniques retain the relative position of the players in the hierarchy, but make it easier to "catch up."

Finally, some systems impose fixed prices on items that are decided upon in advance rather than conducting an auction. This system, "Fixed-price DKP" has the advantage that it is very quick to administer while running a game, but suffers from the deleterious economic effects of these price controls (See Price Controls below). DKP or dragon kill points, is a point system used in online games, specifically MMORPGs such as World of Warcraft and EverQuest II, to distribute items among groups of players. ...

Other DKP systems

Some other systems that also call themselves DKP are in use, but often differ substantially in their mechanics. The sections below provide a sample of some of the systems that are in use. The exact mechanics used by each guild are often slightly different, or they may use elements from multiple systems. As such, this list is not comprehensive.

Zero-sum DKP

In this system, every item that can be received in a particular encounter is assigned a point value in advance. When such an item drops, players, in priority of their total number of points, have the option of receiving that item. If a player elects to do so, then everybody else participating in that encounter receives an equal fraction of the points just spent. Players are allowed to have negative points. The total number of points spent is always equal to the points received, which is the origin of the name "Zero-Sum".

Here is an example to make this concept clearer. If we have a group that meets a challenge resulting in an item costing 80 points, and there are 40 members of the group, then everybody in the group would have 2 points added to their totals (80 point item divided by 40 group members). The person who receives the item would lose 78 points total (spent 80 on item but gets their 2 point share). In order for the person who just spent 78 points to get another item, he or she would have to wait until his or her total points were at least as high as the other members of the group. The final result here is a sort of round-robin scheme, weighted by the value of the item that was awarded. Round Robin = A sexual act between two partners. ...

Proponents of zero-sum DKP argue that it allows newer members more of a chance to receive items, since group members will often go into negative points after receiving particularly valuable items, and new members will start at zero points. However, the effect of this system is to assign both a price ceiling and a price floor to the "DKP Market," which carries its own advantages and disadvantages. (See Price Controls below). DKP or dragon kill points, is a point system used in online games, specifically MMORPGs such as World of Warcraft and EverQuest II, to distribute items among groups of players. ...

This system is mostly immune to collusion attacks, assuming that a strategy for unwanted items is chosen that prevents collusion.

Spend-all DKP!

In spend-all DKP, whenever a player decides to purchase an item, that player is required to spend all of his or her current DKP to purchase it. Items are assigned in priority order of number of DKP. This is intended to ensure that newer players will be able to receive items even in a mature DKP system, but that veteran players will be almost guaranteed to get items they have been trying to get for a long time.

The biggest problem with this system is that players are frequently unwilling to spend all their points on certain items, meaning there will be lots of unwanted items. Also, in spend-all DKP, players will not have as much incentive, once they are the current point leader amongst competing players, to participate in encounters that do not have a chance of producing the specific item they are looking for, other than participating just frequently enough so as to remain the leader.

This system is mostly immune to collusion attacks, assuming that a strategy for unwanted items is chosen that prevents collusion.

Spend-enough DKP

Spend-Enough DKP is intended to achieve some of the results of spend-all, but in a less extreme manner. In Spend-enough DKP, players are given priority in order of point total. Eligible players are polled in priority order, and if a player wants an item when their turn comes, that player must spend DKP in an amount 1 greater than the next-highest eligible player. This allows players to keep some DKP, but acts as though everyone of lower priority wanted the item and assumes that those players would have bid up the item to that point. One of the primary advantages to this approach is simplicity of administration, since players are merely required to announce their candidacy for an item and the raid leader can determine everything needed from there.

While not as severe as in spend-all, spend-enough DKP can lead to unwanted items.

This system is mostly immune to collusion attacks, assuming that a strategy for unwanted items is chosen that prevents collusion.

Probabilistic DKP

Rather than directly spending DKP to purchase items, some guilds instead use the DKP total of players to influence their probability of receiving the item in a random roll. For example, if one player has 20 DKP and another 10 DKP, the player with the higher total might have twice the chance on a given drop to receive the item. The DKP total of the winning player is then reduced by a predetermined item value.

Strategies for dealing with unwanted items

In any system, but especially those that have some sort of effective price floor, there will be items that are not wanted by any member of the group involved. Different clans or guilds deal with this issue in different ways. One way is that a leader of the guild will assign the item to a particular player, either forcing that player to pay a DKP price for the item, or simply basing it on who is deemed to most benefit from it, or some other factor. A random roll could be used. Some guilds maintain a "guild bank" where such items are stored until and if someone should want it if this is possible in that game.

Note, however, that often a DKP system may have been designed the way it is to prevent collusion between players. If your DKP system has a mechanism for assigning an unwanted item, then this may itself be used as a means of collusion amongst players unless players are forced to pay for the item.

The economics of DKP

Since the intention of DKP is to allocate scarce resources amongst guild members, it can be understood in the context of economics. In particular, we should consider the effects of such systems on the supply and demand that combine to determine the prices of items. Buyers bargain for good prices while sellers put forth their best front in Chichicastenango Market, Guatemala. ... The supply and demand model describes how prices vary as a result of a balance between product availability at each price (supply) and the desires of those with purchasing power at each price (demand). ...

Understanding how the supply of items works can be somewhat problematic. In a normal economy, supply is created through the efforts of agents in the economy to use resources to create goods or services for sale, and indeed, items in a MMORPG are generated by the efforts of players. In games such as World of Warcraft, however, some items can only be used by the player who originally "loots" the item. Such items are called Bind on Pickup (BoP). Other items can be sold or given away after being found. In World of Warcraft terminology these items are Bind on Equip (BoE). The supply of these items is therefore somewhat quirky, as only those players present at a particular encounter can receive an item. For the most part the supply is a fixed constant times the number of times a particular group completes a particular encounter. World of Warcraft (commonly abbreviated as WoW) is a massively multiplayer online role-playing game (MMORPG) developed by Blizzard Entertainment. ... Bind on Pickup is a term used in the MMORPG World of Warcraft. ... World of Warcraft (commonly abbreviated as WoW) is a massively multiplayer online role-playing game (MMORPG) developed by Blizzard Entertainment. ... Bind on Equip is a term used in the MMORPG World of Warcraft. ...

Once a player has a particular item, there is no need for him ever to get another one. That is, the marginal utility of the second copy of that item is zero, while it is high for the first copy of items useful to that player. When an encounter is new or has not yet been defeated often for a particular group, the demand for the items from these encounters will be very high. However, after the encounter has been completed many times, most players will already have all they need of a particular item, and thus the demand for it tends to fall off dramatically. In economics, marginal utility is the additional utility (satisfaction or benefit) that a consumer derives from an additional unit of a commodity or service. ...

The net effect of a roughly fixed supply and a rapidly decreasing demand is that the DKP value of items starts very high when a guild is new and then rapidly crashes as the guild matures, eventually approaching a steady state controlled by the rarity of the item, its relative value, and the rate of inflow of new members and exit of existing members. Indeed, this fact is the reason some groups opt for fixed-price systems, since some members feel it is unfair for them to pay the early high prices and new members pay the lower prices after the price crashes.

Sidebar: Is the major premise of DKP systems flawed?

Essentially, the premise underlying DKP systems is that a player should be rewarded relative to their efforts. However, it is still a very controversial subject as to whether the concepts of "value" and "effort" supporting DKP systems are essentially flawed due to ignorance of statistics or the concepts are valid in a broader social context.

The premise is flawed

It should be noted somewhere that a major premise regarding what makes DKP systems valuable in the eyes of its proponents is incorrect. For example: The probability that a rare and valuable item drops on a given run is not affected by the fact that it has not dropped on many previous runs. It doesn't matter if you ran a dungeon 20 times or one time before it dropped. Therefore logically only the people that are there when it does drop are responsible for producing the item, and the people who ran it previous times have no legitimate claim.

Though it may be perceived as unfair by people with a poor understanding of statistics that a person who ran the one time gets an equal chance to receive the item and possibly does receive the item, it may not be perceived as unfair by someone who understands probability. In this case educating people would be just as effective as replacing the often embedded random systems with much more complicated systems that rob casual players of their equal chance to get rarer items when they are there.

See memorylessness, or geometric distribution for verification of these claims. In probability theory, memorylessness is a property of certain probability distributions: the exponential distributions and the geometric distributions. ... In probability theory and statistics, the geometric distribution is either of two discrete probability distributions: the probability distribution of the number X of Bernoulli trials needed to get one success, supported on the set { 1, 2, 3, ...}, or the probability distribution of the number Y = X âˆ’ 1 of failures before...

Regarding the "Players who put great effort in obtaining a particular item should be able to get it reliably" issue, again it should be noted that this is only fair to other players by any standards if he is giving up items equal in value to that which he is being guaranteed on a dungeon run where this rare item drops. If a dungeon can only be run once a week, and that player (lets call him a farmer) goes every week only wanting one rare item, he does not cause the item to be produced more often than if he still wanted everything the dungeon had to offer. If he is given this rare item because of his prior efforts, his teammates are being taken advantage of unless they are given something equal in value to their chance to get the rare item, and while the increased probability of getting items that the "Farmer" no longer wants or needs is worth something, it is often not worth as much as the chance to get the rare item the "Farmer" still wants.

One might also wish to consider the elements of human nature that go into making DKP systems popular. If someone runs a dungeon 10 times and was not able to produce the item he will be frustrated. He will be looking for anything or anyone he can blame... and someone that doesn't understand that the unlucky raider's previous efforts towards getting an item did not contribute to the items appearance when it happens to drop is the perfect target. Without this knowledge to use to defend himself it only makes sense that he would feel he has no choice to give in to the selfish demands of the unlucky raider.

Regarding the order in which clan members get desired loot: The argument here is all present members contribute equally to an items production, therefore each present member has an equal right to all items. This means only a random determination of who gets the item first is fair. It may be true that even with good leadership more experienced players, while not effecting the probability of success, might affect the ease with which the raid is coordinated or other similar abstract attriburtes of the raid. However this is in no way entitles experienced players to receive loot first. A simple example: A raid leader spent 5 minutes less time preparing or coordinating a raid because his group of healers already knew what they had to do. This is in comparison to a person's say 1/8th chance to receive a desired item on a 4 hour raid. (30 minutes) Or the 21 hours worth of time lost due to giving up loot on an instance run where the instance prevents entry for a week after. Also the raid leader can simply make understanding tactics a prerequisite of coming to a raid, and post all needed information on the clan site. Therefore the signifigance of experience would be completely mitigated.

The premise is not flawed

On the other hand, while mathematically accurate, the above argument is incomplete and doesn't take into account the additional social context of the problem. For example, say 5 people all want a specific item and it drops with some probability P. Over a long enough time interval it is highly probable (given the probability distribution function of the drop) that all 5 will eventually get the item. What is not considered is the order in which people will get the item. If the order of assignment is also random (as suggested above), then the worst case scenario is that the most veteran player is the also the last to receive the item rather than the first. This is intuitively "unfair" to many people, and rightly so: the veteran in this situation has spent more effort acquiring the item than any other person. In mathematics, a probability distribution assigns to every interval of the real numbers a probability, so that the probability axioms are satisfied. ...

While it's true that this "worst case" is itself only one of 5 random assignment outcomes ("best case" is the most veteran gets it the first drop), many people are willing to trade uncertainty in assignment order for a more predictable assignment system roughly correlated to effort.

Note also that DKP is primarily only used in "high-end" or "end-game" instances, where there is considerable time and effort necessary in order to kill a boss. In lower level instances it is usually common practice to revert to the simpler random roll systems:

• lower-level instances are primarily pick-up groups vs. guild raids. (constant shuffling of party members makes it hard to make a claim of senority in such groups).
• random roll is embedded in most MMOs.
• the effort to kill is much less
• there are usually fewer "cooldown" periods for such instances where people cannot repeat an instance for a certain amount of time (usually a week) even if they want to.

-Another point to consider is utility to the guild. DKP tends to reward those players that are more likely to contribute to the guild in the future based on historical performance.

The premise is not mathematically flawed

While the above mathematical argument is correct given the assumptions made, it does, never the less, not give an accurate picture of the fairness of DKP systems. The assumption that the chance of a given item drops is independent on whether is has dropped previously is true, but the chance of a certain player getting the item is indeed dependent on previous drops.

This is due to the fact that the veteran player already having equal or better items usually will usually not be allowed to roll on an item, thus the chance of receiving an item during any particular encounter is greater for the new player than the veteran player. Essentially players are rewarded for their effort with a chance that they will receive an item, but as their reward is reduced by already possessing items, new players are getting a greater reward than veteran players for the same amount of work. To offset this phenomenon a DKP system can be used, ensuring that when a players reward is removed (not being allowed to roll), a compensation is made by increasing that players chance of receiving future items.

Price controls

Some systems, such as zero-sum and fixed-price, impose price ceilings, price floors, or both. A Price Ceiling is a government-imposed limit on how high a price can be charged on a product. ... A Price floor is a government-imposed limit on how low a price can be charged for a product. ...

The effect of a price floor is that there will often be situations where nobody is willing to spend the required number of points for a particular item, necessitating the need for some means to resolve this difficulty. See "Strategies for dealing with unwanted items" above for more information on how this can be handled. DKP or dragon kill points, is a point system used in online games, specifically MMORPGs such as World of Warcraft and EverQuest II, to distribute items among groups of players. ...

The price ceiling means that there will be situations where more than one player will want it at the given price. This is generally easier to resolve than items not being wanted at all, since falling back to random roll amongst those players that can afford it is usually considered fair in the sense that all players being allowed to roll are deserving of the item as defined by the point system. If prices are set too low, however, too many players will have enough points to purchase items and much of the purpose of a point system in the first place is lost.

External links

• DKP Log Parser: An open source tool for managing DKP awards based on time spent in a raid.
• EQdkp: an open source program that guilds can use to manage their own DKP systems.
• Nurfed DKP (NDKP) A DKP program devoloped by the guys at NurfedUI, primarily centered around World of Warcraft