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Self-sustainable Agent Organizations in MassivelyMulti-Player On-Line Role-Playing Games – A Conceptual

Framework

Igor Tomicic, Markus Schatten, Bogdan Okreša ÐuricUniversity of Zagreb

Faculty of Organization and InformaticsPavlinska 2, Varaždin, Croatia

{itomicic, mschatten, dokresa}@foi.hr

Jurica ŠevaHumboldt-Universität zu Berlin

Institut für InformatikUnter den Linden 6, Berlin, [email protected]

Abstract. Massively On-Line Role Playing Games(MMORPGs) costitute an ideal test-bed scenariofor the development and testing of large-scale agentorganizations. In this paper the possibility of us-ing a recent agent-based framework called SmartSelf-Sustainable Human Settlements (SSSHS) inagent based organizations is analyzed. We provide aconceptual framework for integrating SSSHS into amodelling tool that is being developed as part of theModelMMORPG project that aims on establishingan organizational methodology for the developmentof large-scale multi-agent systems (LSMASs) in thecontext of current phenomena like the Internet ofThings (IoT), smart cities and MMORPGs.

Keywords. smart self-sustainable human settlementsframework, mmorpg, agent based modeling, agent or-ganizations

1 IntroductionThe ModelMMORPG project aims on developing andtesting various organizational methods for large-scalemulti-agent systems (LSMASs) especially in the con-text of massively multi-player on-line role playinggames (MMORPGs) which constitute an interestingphenomenon that allows for testing real-life scenarios(M. Schatten et al., 2016). The project analyzes suchgames from two perspectives: social science perspec-tive (development of agent based modeling techniquesto analyze and simulate player behaviour) as well asa computer science perspective (development of vari-ous types of agents like mobs, non-playing characters -NPCs, and artificial players).

Until now, the project team has developed a numberof agent-based modeling techniques (Markus Schatten,Tomicic, et al., 2015) for the development of mobsand NCPs, as well as complex quests with varioustasks that foster organization in player teams calledparties. Additionally, an automated planning systembased on the well known belief-desire-intention (BDI)

(Rao and Georgeff, 1991) model for artificial players(bots) that uses a modified STRIPS algorithm (Ghallabet al., 2004) has been developed as well (Malikovic andMarkus Schatten, 2015).

Beside these methods, we have conducted an exper-iment with a specially designed instance of the open-source MMORPG called "The Mana World" (TMW)1

to analyze player behaviour behaviour. In this exper-iment players were instructed to solve a special questwhich we called "The quest for the dragon egg" whichwas designed to foster organizational behavior. Play-ers were unable to solve the quest by them selves, andhad to organize into parties in order to conduct the var-ious tasks. Detailed data about player behaviour hasbeen collected from this experiment, and part of thedata has been analyzed in (Markus Schatten and OkrešaÐuric, 2015; Markus Schatten and Okreša Ðuric, 2016;Okreša Ðuric and Konecki, 2015), by using a num-ber of methods strongly related to big data analyticsand social network analysis similar to those used in(Markus Schatten et al., 2015a; Markus Schatten et al.,2015b).

On the other hand, in parallel, a framework foragent-based modeling and simulation of smart self-sustainable human settlements (SSSHS) has been de-veloped in (Tomicic and Markus Schatten, 2015;Tomicic and Markus Schatten, 2016). The frameworkallows for modeling of any type of resources in humansettlements and introduces a number of smart mech-anisms to foster self-sustainability. These mechanismsare of special interest to any type of agent organization,since they optimize resource production and usage, andthus allow agents to easier perform their tasks.

In the following we will try to apply these mecha-nisms, if applicable, on a higher level of abstractionto any agent organization which needs to manage re-sources. Then we shall specialize these mechanismsfor player parties in MMORPGs, since player partiesneed to manage their resources optimally, in order tosolve quests.

1see https://wiki.themanaworld.org/ and figure 1

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Figure 1. An open source MMORPG called "The Mana World"

The rest of this article is organized as follows: in sec-tion 2 we introduce the SSSHS framework in more de-tail and discuss it’s relevancy to the ModelMMORPGproject. In section 3 we provide a more abstract viewof the SSSHS framework to be able to apply it to anyresource-managing agent organization. In section 4 weapply this conceptual model to the special case of "TheMana World" MMORPG. In the closing section 5 wedraw our conclusions and give guidelines for future re-search.

2 The SSSHS FrameworkSSSHS is an agent-based framework for modeling andsimulation of self-sustainable systems that has been de-veloped using a modified MaSE (Multiagent SystemEngineering) methodology (Deloach, 2004) that im-plements a number of self-sustainability mechanismsfor resource management and provides a first step to-wards understanding such complex socio-cyberneticsystems. "Self-sustainability mechanisms (...) can bedescribed as those methods, selected and activatedby the framework, which have the ability to prolongthe self-sustainability property of the modelled system"(Tomicic, 2016, p. 51). In SSSHS there are two typesof such mechanisms defined:

1. Lower threshold mechanisms - mechanismswhich are triggered upon an event that indicatesshortage of an observed resource due to overcon-sumption.

2. Upper theshold mechanisms - mechanismswhich are triggered upon an event that indicated

overflow of an observed resource due to overpro-duction.

Lower threshold mechanisms include: (1) the"Economy" mode - in which various appliances useless resources and thus lower consumption, (2) manip-ulation of operating times: delaying - appliances post-pone their operating times to use less resources duringpeak periods, (3) resource negotiation with neighbor-ing sub-systems - appliances try to acquire resourcesfrom neighbors. The last mechanism uses Raiffa’smodel for bilateral negotiation (Raiffa, 1982) and thefinite state machine for the protocol as shown on figure2.

Upper threshold mechanisms include: (1) restoringdefault consumption modes - appliances restore theirdefault consumption mode after peak periods are over,(2) manipulation of operating times: advancing - ap-pliances schedule their operating times earlier to useresources which would else overflow, (3) offering theresources to neighboring sub-systems - appliances of-fer their surplus resources to neighbors.

While these mechanisms are simple in principle, ithas been shown through simulation of various real-world scenarios that they can have tremendous impacton the period some system can self-sustain their re-sources (Tomicic and Markus Schatten, 2016; Tomicic,2016).

3 An Abstract View on SSSHSIn a more abstract view, a smart self-sustainable humansettlement represents an agent organization with es-tablished links of both communication (the social net-

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Figure 2. Finite state machine of the negotiation protocol (Tomičić, 2016, p. 54)

work) and resource exchange (the resource network).These two networks can be considered the organiza-tional network. Agents inside this organizational unitcan be producers, consumers or storages of one or moreresources. The objective of the organizational unit is toproduce enough resources to sustain all consumers ina given time period. The rates of resource productiondepend on a number of complex systems in the envi-ronment - meteorological and other conditions, humancomfort levels etc.

In (Markus Schatten, 2012; Markus Schatten, 2014)we have defined organizational units as follows:

- Any agent is an organizational unit.

- If O = {o1, o2, ..., on} is a set of organizationalunits which collaborate with a common objective,then O is an organizational unit.

The organizational unit defined within the SSSHSframework is a specialization of this definition. The setof agents within the organizational unit is given withthe decomposition 0 = P ∪ C ∪ S, whereby P isthe set of producing agents, C is the set of consumeragents, and S is the set of storage agents. Note thatP ∩ C ∩ S is not necessarily ∅, e.g. some agentsmight be producers, consumers and/or storages simul-taneously. Additionally, let R = {r1, r2, ..., rm} be aset of resources. Then we can define the relations ρ(defined on O × O × R) as the resource network be-tween agents (e.g. which agents exchange which re-sources with each other), as well as four specializa-tions of this network defined as ρP ⊆ P × S × R(which producers store their resources in which stor-ages), ρC ⊆ S × C × R (which consumers use re-sources from which storages), ρCP ⊆ C × P × R(which consumers consume resources from which pro-ducers), and ρPC ⊆ P ×C×R (which producers pro-duce for which consumers). In the end we can defineσ (defined on O × O) as the social network of agents(e.g. which agents communicate with each other), and

τ ⊆ O × R that gives us the information on whichagents use which types of resources.

A similar definition is given by (Krackhardt andK. M. Carley, 1998) in form of the PCANS model, andlater by (K. Carley, 2003) in form of the MetaMatrixmodel, that has been extended in (Markus Schatten,2013).

The objective is specialized as well: let us assumea time-set T isomorphic to the set of natural numbersN. A time interval is then defined as an ordered pair oftwo points in T, representing the time between these topoints in time. For each agent we can define functionsof the form f : O × R × T → R that provide the pro-duction/consumption/storage rates for each given time.The objective of the organizational unit is then definedas the constraint in a given time interval ∀o ∈ O,∀t ∈(ti, tj),∀r ∈ R : f(o, t, r) ≥ 0 ∧ f(o, t, r) ≤ omax

(where omax is the maximal quantity of resources thatcan be stored in a given agent). We read, at each givenmoment in an observed period of time, each agent hasto have enough resources available to function and ad-ditionally avoid overflow of resources.

Such a definition allows us now to model arbitraryagent organizations as SSSHS organizations, as weshall show in the following section.

4 Integrating SSSHS into TMWOne particular example of an agent organization is aplayers’ party in an MMORPG. Herein we will useTMW as an example MMORPG, but most of theconcepts analyzed herein, could be applied to anyMMORPG which allows players to organize into par-ties, guilds, teams or similar organizational units.

In TMW we have developed a special quest called"The quest for the dragon egg" which was designedto foster organizational behaviour between players. Inprinciple, it is impossible for a single player to solvethe quest by him self. One crucial aspect of this quest





is that players need to gather various types of items inorder to be able to get all the ingredients to hatch adragon egg. Since these items are scattered across thewhole "Mana World" and time is limited, they need tomanage their actions as well as their resources. Someof the gathered resources, are also needed for other ac-tivities, not related to the quest (e.g. other quest, gath-ering energy or experience etc.).

From this perspective the various items needed tosolve the quest represent the resources (R) that areneeded for the organizational unit to function. Agents,which can be producers, consumers and storage agentsare the players which gather the items (by fightingmobs for example), NPCs which take the items to cre-ate other items or provide the players with certain pos-sibilities (like the ability to enter a secret room), banksor vaults that enable players to store items when theyhaven’t enough space in their local storage (the socalled "back pack") etc. All these types of agents rep-resent various elements of sets O, P , C and S.

In a party (artificial agent organizational unit) whichtries to solve a quest, all of the aforementioned self-sustainability mechanisms can be applied to make theorganization more efficient in terms of resource man-agement. For example the "Economy" mode, will bethe default behaviour for resources that are needed fora given quest - players who gather such items will notuse them for any other tasks, except if it is unavoidable.

Delaying and advancing can (and has to) be usedsince when some items aren’t available, then they can-not be used at a given time to perform some task. Also,if there is surplus for a given item, it can be used muchsooner then planned.

Negotiation and offering of resources is crucial tothe functioning of the party and solving of the quest.Most items cannot be gathered by only one player,which is why players have to exchange their gathereditems, for the whole quest to be successful. By usingvarious negotiation techniques, by for example includ-ing transport costs as a negotiable variable, this processcan be optimized.

5 ConclusionIn this paper we have shown that it is possible to use theSSSHS framework for building agent organizations inthe context of MMORPGs. We have provided an initialconceptualization of the framework that allows us touse it in any agent organization. Additionally, we haveshown a simple example of how such a framework canbe used to solve a special quest that has been developedfor the open source MMORPG TMW.

Our future research will try to integrate this frame-work into an ontology of organizational design meth-ods for LSMAS, and consequently into a metamodelfor a modeling and development tool. We hope that thistool will allow us to model various types of agent orga-nizations applicable in numerous areas like IoT, smart

cities and MMORPGs.

AcknowledgementsThis work has been supported in full by the CroatianScience Foundation under the project number 8537.

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