Loot system

A Loot System refers to a system of distributing items ("loot") amongst a group of players in a game, most commonly in a Massively Multiplayer Online Role Playing Games (MMORPG).

The Premise of a Loot System

Loot Systems exist solely because of the game mechanics of popular MMORPGs. One of the primary objectives in this genre of game is to improve one's character, the representation of the player in the virtual world. The common ways to do this involve obtaining experience or by upgrading the items (loot) the character uses. In the most popular MMORPGs, such as EverQuest or World of Warcraft the amount of the experience the player can obtain has a hard limit, so much of the player's improvement must come from loot.

Herein lies the dilemma: One mechanism by which loot is obtained is the completion of content built by the game developer. This often occurs by defeating a difficult non-player entity, or "mob". The mob, once defeated will award loot. However, since the design of MMORPG is meant to be one that rewards players who work together as a group to complete the content, there are often multiple players who desire the loot that has been rewarded (or "dropped"). This is where a loot system becomes important, as it attempts to allow a fair and equitable method for players to decide who gets what.

Loot System Classes

There are obviously multiple ways in which this decision can be made. Systems range from a reflex based, first come first serve method to an almost dictatorship-like system where the appointed leader of the group awards the loot to players he or she feels deserve it. However, most players enjoy a system that gives equal chance to all who were involved and removes any real or perceived favoritism from the decision.

"First Come First Serve"

The most simple loot system is one of anarchy. The players who have the fastest reflexes to perform the action necessary to receive the loot do so. This has several obvious downfalls which tends to aggravate players:

*Reaction time is often hindered by outside forces such as lag or other game mechanics.
*It can ruin the cooperative nature that many players enjoy about this genre.

Random Number Generation Based Loot Systems

The overwhelmingly most used loot system class is one where the decision on which player receives which items is completely based on a public random number generator. This type of system completely removes all human input from the decision, and gives an obvious statistically equal chance to those players involved. Using random number generators for the basis of a loot system is so common that many games have coded the system directly into the game experience to expedite the process. Due to the similarity between using a random number generator and rolling a die (or set of dice) the process is referred to as "rolling" and the act of "rolling for loot" is the process by which players are assigned a number by the random number generator which determines if they will obtain the desired items.

Pure Random

A very simple random system which just assigns the loot to a random player in the group regardless of any other factors. This variant is a common method for distributing loot that has only monetary value ("trash loot") and is often coded into the game. It is not usually used for items which players might equip, due to game mechanics.

"Need Before Greed"

The vast majority of MMORPG games have some sort of class system, where each player can choose a class which allows them certain skills, as well as placing certain restrictions on which items the player can use. Players of a certain class also prefer items which have attributes which improve statistics which give benefit to the primary skills of their class. Thus, each player often does not desire the same item, as a group of players generally has several of these classes in its makeup. However, many items also have some value in the in-game currency, so there is often some interest in the item from all players involved. The "Need Before Greed" system allows players who will make the most use of the items have priority over those who only desire the item for its monetary value, such that only the subset of players who will benefit the most are allowed to "roll" for the item. If no players desire the item, then a pure random system is used to determine who obtains the item for its monetary value. This system can be very straightforward and simple, especially in smaller groups of players where perhaps only two or three players desire the same item. However, this system also has some perceived downfalls which tend to aggravate players:

*Deciding "Need" can be a difficult task due to the different playstyles and overlapping class needs and restrictions that exist in game mechanics. This can (and does) cause heated debates about which player receives the "most" benefit from an item.
*Players can deceive other players in the group about their need, when they really desire the item for its monetary value.
*No consideration is given to players who have completed the content many times compared to players who have only completed the content a few times.
*There is no cost involved in the act of rolling, nor any influence on the ability to get loot in the future, so there is little reason not to attempt to obtain any item you could reasonably use.

These perceived downfalls often cause various extra restrictions to be placed on the system such as:

*Democratic decisions on which player has the most "need".
*Restrictions on the number of items a player can get during one time period.

Point Based Loot Systems

Point based loot systems have arisen for a number of reasons. The first is that players feel that their previous attempts and completion of the content that contains the loot they desire should somehow determine their priority over other players, which is obviously impossible in a random system due to memorylessness. Players also often feel that items should go to the player that has a high amount of desire for it, something impossible to quantify in a random based loot system. Lastly, a common game mechanic is to place the most highly desired items in content that requires very large amounts of both time and personnel to master and complete, meaning that players are even more aggravated by the downfalls of a random based system as described earlier.

Since statistically, over time, all players will move towards receiving the items they want, point based systems do not determine anything but the "order" in which the players get the items.

Common problems with point based system problems include:
*Point inflation - points are earned faster than they can be spent, meaning that less frequent participants can never hope to catch the top point holders.
*Collusion - some systems are vulnerable to players colluding with one another to gain advantage over other players.
*Dealing with unwanted items.

Earning Points

Obviously to be able to spend points, there must exist a method of earning them. There are two main methods of obtaining points in a point based loot system, time based and content completion based. These two systems are often modified in a variety of ways, usually to reward (or demerit) players for certain behaviors or to provide incentives them to participate in certain content. Regardless of the method, the players are rewarded for participation in the content so that players who participate most frequently obtain a larger ratio of the loot obtained, or perhaps more correctly, a larger ratio of the total "desirability pool" of the content.

Content Completion Point Earning

Often there are milestones in the content players participate in. The system rewards point rewards for certain milestones, regardless of the amount of time required to reach them.

Points of Consideration
*Encourages quick completion of content as it will increase the points/time ratio for all involved.
*Allows content leaders to award larger point values for certain milestones.
*Can cause low incentive to learn new content, as the points/time ratio can be very low if the content has a steep learning curve.
*Content is not required to abide by a time schedule and players who can simply stay longer are rewarded for poor planning on the part of the leader.

Time Based Point Earning

In this method, points are simply awarded for the amount of time the player chooses to participate in the content.

Points of Consideration
*Purely time based point earning rewards players who participate in content before it has been mastered as they receive full value for their time, even if little content is being completed. This encourages players to come and help learn content at an early stage, rather than waiting until others have done the (often difficult) task of mastering the content.
*Can allow content leaders to simply schedule a set time for content participation, only awarding points for the time window set for the content.
*Does not inherently encourage speedy completion of content as there is a fixed point/time ratio.

Converting Points into Items

The largest differential between the various point based loot systems is the method by which points are converted into items, or priority to receive items. These systems can be described as three subsets, fixed cost, auction bid, and constrained bid.

Fixed Cost

A fixed cost system (or "purchase system") is one where each item that has a statistical chance to drop in the content the players are currently participating in has been assigned a point value. These values can be derived in a number of ways, from gauging desire for the item compared to its probability of dropping (simple supply and demand) to a method based on the attributes of the item. In this way items are purchased with some created currency that players can earn. Since each item no longer has zero cost to each player, players now must consider the opportunity cost of the item, as it will impact their ability to obtain other items.

Points of Consideration
*Each player pays the same cost for the item regardless of when it is received, meaning that players who participate less do not have a better points/loot ratio than players who participate more frequently.
*If multiple players can afford to pay the cost for the item, another system (such as a random loot system) must be used to determine which player will receive the item.
*Players must decide what cost to assign each item, meaning that human bias enters the system.
*Collusion between players is not possible as the cost for each item is fixed.

Auction Bid

In an auction bid system players can bid any amount of their current points on an item. The bids can be made public or done in secret, depending on the variant of the system. Much like a fixed-cost system each item now has a non-zero cost to the player, but now the cost of each item is purely dependent on the market forces created by the player pool which desires the item, rather than an artificial system which can be open to discussion.

Points of Consideration
*Bid collusion between bidders is possible in some cases, due to game mechanics. Often, some items are only usable by a very small subset of players, while other items by a larger subset. If players in the small subset all agree to bid low on those items, that gives them an advantage on items in a larger subset.
*On average the cost of each duplicate/similar item received is lower, as the subset of the players who desire the item gets smaller. Thus players who participate less frequently will on average have a better loot/time ratio.
*Private auctions could be tainted by collusion between the auctioneer/content leader and specific players.

Constrained Bid

In a constrained bid system players are forced to bid a certain fraction of their current points. Thus this system is inherently different from a fixed-cost or auction bid system in that points don't determine purchasing power as much as they do a player's ability to exercise priority over another player. Points only serve to quantify how many places "in line" a player loses for receiving an item or gains for participating in content.

Points of Consideration
*Bid collusion is not possible since players cannot choose the size of their bid.
*Low desirability items may not get any bids, since the bid is fixed.
*By choosing the size of the constrained-bid content leaders can encourage a certain loot distribution.
*Players can choose to save points to receive first priority on a highly desirable item at a large cost, or bid often and receive multiple lesser desirability items for lesser cost.

Loot Systems in Use

There are many loot systems in current use, this list is not comprehensive.

*DKP - The name DKP really refers to a set of loot systems, variants of which fall under several of the categories outlined above. The common thread that exists for all DKP is that points are earned via content completion and that each player has a point total that can be spent in some manner on items. The list of variants is summarized here.
** Basic DKP - simple auction bid system
** Zero-Sum DKP - a fixed cost system that removes point inflation by giving all participants an equal fraction of the points spent on an item by a single participant.
** Spend-all DKP - a constrained bid system where the only allowed bid is all points.
** Spend-enough DKP - a constrained bid system where the only allowed bid is 1 more than the next eligible player's point total.
** Probabilistic DKP - a hybrid between a fixed cost and a random number generator system where points are used to weight the statistical chance the players will receive an item.
*Shroud Loot System (SLS) is a time based point earning, constrained bid system. SLS uses a half point bid but also allows a small fixed cost bid to be placed on items, to ensure that even items of low desirability are distributed. This system allows frequent participants to receive items first, but at a worse loot/time ratio than less frequent participants. The original incarnation of this loot system can be found [http://www.shroudguild.org/sls/rules.php here] .
*Ladder/Reel is a constrained-bid system that doesn't use points. Players simply take turns having top priority. Very similar in distribution method to a Spend-all DKP system. Suicide Kings is an example of a Ladder/Reel system.