Interactive Storytelling in Multiplayer Role-Playing Games

TABLE OF CONTENTS

1. Introduction
1.1 Motivation
1.2 Aims
1.3 Project Intention

2. Fundamentals
2.1 Fundamentals of Multiplayer Gaming
2.2 Fundamentals of Adventure Games
2.3 Fundamentals of Interactive Storytelling
2.4 Related Works

3. The New Game Concept
3.1 Problem Analysis
3.2 Concept Description
3.3 Evaluation Criteria

4. Exemplary Implementation
4.1 Requirements Analysis
4.2 Software Architecture
4.3 Implementation Details

5. Case Study
5.1 Design of Sample Game
5.2 Execution of Case Study
5.3 Evaluation of the Results

6. Conclusion
6.1 Summarisation
6.2 Future Prospects
6.3 Critical Evaluation

Bibliography

Appendix

ABBREVEATIONS

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“Someday [Interactive Storytelling] will be a new industry, quite distinct from games. Right now, it's nothing, but it feels to me just like "the good old days" back in the 1970s when computer games were fresh, untried, and bursting with

potential.”

Chris Crawford, founder of the Game Developers Conference

CHAPTER 1:
Introduction

In this chapter will be described in which subject area the present Master‟s thesis is located, which motivation led to it, which aims were set and how these are to be achieved.

1.1 Motivation

This section shall clarify the underlying motivation of this research project and Master‟s thesis. By what has it been initiated and why? What does the new concept consist of and which problems are raised by it?

The first computer games wherein a story was in the foreground (that is, games of which the focus is the playing of a plot) constituted the game genre Adventure^[1]. Contrary to other computer games that for example mainly focus on competing with other players or scoring, classic Adventures contain a single predetermined, hardly interactive story, played by a single player who starts at a single preset initial point and has the aim of achieving one or more preset end points of the game plot (representing beginning and ending of the game story). To advance and experience this for the most part preset story is the main focus and source of gaming fun of Adventures. For on the one side their mostly linear plot allows the player only a limited and rather small number of freedoms of action (mostly confined to the order of visiting places, solving riddles, conversations etc.) and on the other side these actions mostly result in little influence on the main story (if at all then mainly in different story endings).

Not long after the first Adventures the game developers realised that the players of narrative games wished to have more influence on the story than mainly to follow it almost as if watching a movie or reading a book (of which the plots are fully linear and the stories entirely non-interactive) – for certainly it would be more enjoyable and entertaining for a player to have more freedom of action giving the own actions more meaning. Due to the technological progress back then it was still too early for truly interactive stories so game developers broke the new ground with small steps: for example the player could choose from a number of gaming styles that alter the nature of the further story by changing the behaviour of the played character in the game^[2]. The next step in story interactivity was taken with Adventures that offered alternative endings, depending on the decisions made by the player during the game (and rather close to the end of it). Still these rather small “freedoms” weren‟t fully satisfying – neither for game designers nor for players.

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Figure 1-1

Screenshot of The Curse of Monkey Island: The love story between the player character and a NPC is a strong emotional and narrative element in all four Monkey Island releases.

© LucasArts 1997

Already during the eighties attempts had been made to develop interactive dramas^[3] – with insufficient success and contrary to the success of the very popular gamebooks of that decade. Therein the reader could decide on the course of the story by jumping to other pages within the gamebook depending on his choices.

But back then the limited storage capacity of discs, the large expenditure of time and the high costs of productions allowed providing only few story variants and alternative scenes for possible player choices and these again not much player freedom and variety within the gameplay. Only lately interactive dramas have overcome the old difficulties and appeared successfully as different kinds of Adventures in the world of computer games^[4].

The question emerges why games that base on interactive storytelling are becoming so popular (an indicator is the ascertainable increase of commercially produced interactive-narrative games). Two main reasons can be extracted: story and interactivity. Enthralling stories can be quite simple: good against evil, small and weak become big and strong, man loves woman against obstacles – nonetheless stories like Lord of the Rings (the main story can be summarised in a few sentences!) lure crowds of people into the cinema and make them feel with the characters or abduct them into other worlds, says P. Steinlechner. [Steinlech04] Why would that be different for playing a computer game with an entertaining, dramatic, and surprising story? Games that purely base on shooting can mostly not keep up here (stories are even drawn on to make for example shooters more enjoyable) – as little as movies or books with a bad or hardly any story. (cf. Figure 1-1)

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Figure 1-2 Screenshot of the MMORPG World

of WarCraft: Multiple players playing together; almost all game characters are controlled by real persons.

© Blizzard Entertainment 2006

Now let us imagine the story could be controlled by the person who experiences it and pushes it forward. Thereby this person becomes contributing part of the story instead of watching it from the outside. What could be more thrilling and enjoyable? The answer is: not being the only real person to influence the participated story ! Since mankind plays games those games played by multiple players have almost always been enjoyed much more. Mostly playing on your own is not as much fun, and computer controlled characters (aka non-player characters; in the following abbreviated by NPC) are just no adequate replacement for real human beings (at least at the current state of the art; the researches on artificial intelligence might overcome this matter sometime in the future).

Game designers became aware of the multiplayer factor: a complete new genre arose: “Massively Multiplayer Online Role-Playing Games” ^[5] (in the following abbreviated by MMORPG) being indeed extremely popular nowadays (cf. Figure 1-2). Meanwhile, more than 25 years after the first played stories, thousands of players meet online to play together an uncountable number of smaller stories that behave like television series [Orive05] rather than classic stories in books: the beginning, the propositions are well defined whereas there is no ending. All the small, playable stories are integrated into a larger frame that remains relatively unchanged by player caused events. The players‟ actions in and the interactions of the players with the story world are relatively meaningless as well as the existence of a character is. For only the character itself advances but not his story universe.

Then why not transfer this principle of not playing alone to classic interactive-narrative games?

Altogether Interactive Storytelling in all its variations has taken a long and very manifold way since the first Adventures with their mostly linear alternative story-lines that could be chosen by the player but not be influenced, throughout to story universes with large numbers of foreign co-players and small playable and rather meaningless stories that are far away from the satisfying, captivating dramatic structure until it reached real-interactive Adventures full of different storylines, mutually dependent events and endings.

Nonetheless Interactive Storytelling games haven‟t reached multiplayer status yet. But why is multiplayer gaming so fascinating and popular? Computer antagonists are anonymous, have no personality and behave mostly quite dumb, says Teut Weidemann from Wings Simulations. Real persons are unpredictable, which makes the whole matter enthralling [Weidem04]. Mark Skaggs, producer of The Battle for Middle-Earth, also sees a social component: People watch movies in cinemas together, visit concerts and have coffee together. Playing computer games together is just another form of spending time with other people [Skaggs04]. Why shouldn‟t all this hold for Interactive Storytelling games as well?

Thus the present Master‟s thesis is motivated by a new game concept: a unique combination of Interactive Drama, Adventure and Multiplayer Role- Playing Game, initiated by the just now discovered lack of Multiplayer in Interactive Storytelling. I expect that the extension from one player to multiple players results in the same effects like almost every other game genre extended in the same way: better entertainment, and more “enjoyability” and “enthrallingness”.

The new concept includes that multiple players (in limited numbers, not masses) shall have the ability to commonly develop the plot they are playing; the course of the unfolding story shall depend on the players‟ actions. Thereby each player shall possess his own character as well as his particular relevance within the game and the emerging story. Furthermore they shall communicate with each other enabling them to discuss game situations and make common decisions. This aspect of the game concept creates a strong second level alongside the narrative one: the social level. Both levels take up the same value in the new concept.

Interactive Storytelling yet comes with a certain difficulty: the dramatic art of the story. A good story needs to be dramatic; this also holds for stories in games and directly correlates with the gaming fun. However, in Interactive Storytelling the game story needs to be interactive. That means its plot^[6] has to contain alternative events. These alternatives make it now difficult to ensure a dramatic course of the story that emerges by playing. The more freedom of action concerning the plot is given to the player the more complicated gets the maintenance of the dramatic art of the story the players unfold. The development of approaches to solve this problem which is raised by the interdisciplinarity of interactive but dramatic storytelling represents the “holy grail” of Interactive Storytelling.

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Figure 1-3 The Dramatic Arc (simplified) The story begins with an introducing exposition, rises to the point of highest suspense, and ends with its resolution.

Fairy tales, movies etc. underlie this approved classical narrative structure.

Thereby one major problem to be solved is just the same as the one of single-player interactive dramas: the challenge of combining a well-balanced and dramatic plot for successful storytelling and the interactivity of the player so that his actions noticeably influence the advance of the story [Hartm07]. Additionally a second difficulty needs to be conquered: the establishment of the mentioned social level, i.e., of really making decisions together and not each player on its own. This new problem separates the new game concept from any existing related works.

Thus the first, known problem is now raised to a higher level since it needs to be solved for multiple players who shall all be able to sense the consequences of their gaming actions onto the played story which in turn still shall follow the dramatic arc^[7] (see Figure 1-3) – a complex challenge since it raises the image of a huge space of actions and consequences. For the second, new problem it needs to be examined how this matter can be realised in a multiplayer interactive drama. How can the game designer get the players to work together for achieving a common aim? How may cooperation be promoted instead of egoistic or even antagonistic behaviour?

These problems and questions shall be solved by the present Master‟s thesis.

1.2 Aims

This section shall clarify what I want to achieve with the present research project. The aim of this Master‟s thesis is a scientific one: it shall answer the following questions: Does the new gaming principle work at all? Does an interactive drama for multiple players even come as expected with more gaming fun than single player interactive dramas? (The mentioned expectation arose from the discussion in the previous section.) The accomplished thesis will provide knowledge about whether the expectation could be confirmed. Does the new game concept provide a lot fun-to-play? If yes: Why? And if not: Why not? Can an interactive game story still be dramatic even if more than one player controls its development, i.e., is Interactive Storytelling suitable at all for multiple players?

How do I intend to achieve this aim? Thereto a complete game concept of an interactive drama for multiple players shall be developed and exemplarily implemented. Afterwards a case study that uses the sample implementation will allow examining the expectations as well as the answering of the arisen questions. To allow a critical, useful examination of the project results evaluation criteria will be defined serving the purpose of measurably evaluating the project. Thereby it is important that the implementation represents the concept adequately since the case study and evaluation criteria work on the implementation and not the concept. (The implementation adequately represents the concept if each aspect of the concept can be found in the implementation.)

Furthermore aims for the new game concept were set that differ from the project aims. These are of rather practical nature and describe the following appraisable final states and shall be attained as described in the following:

A) Story interactivity: The final story is a product of the actions of all participating players (within certain, fixed limits, and excluding the beginning).

In order for the story to be truly interactive the players shall be given a number of alternative actions (that influence the development of the story) whenever the player-character is active within the game. The players shall choose the action to happen.

B) Narrative structure: The story is a drama, that is, it follows the dramatic arc. To establish a dramatic arc on the played story the game shall begin with an introduction of the players into the story creating a conflict and an aim that is to be reached and that resolves the conflict. Between beginning and ending the playable story cannot be completely free developed by the players but shall stay within certain borders. This smaller space of events shall allow maintaining the dramatic arc.

C) Fun factor of story: The emerged story is suspenseful, entertaining and sensible.

The story shall become sensible by assigning each action with a sensible consequence. For example, not saving the character or choosing a senseless action could result in the death of the character in the worst case. Furthermore some actions shall be purposeful whereas others shall not. This will provide the option of making sensible decisions.

An entertaining and suspenseful story shall be achieved by providing the players with surprising and rewarding story events. Also a lack of time in solving a conflict situation shall increase the suspense of the players.

D) Flow of gaming fun: The players shall continuously be kept in the flow of gaming fun.

This flow shall be perpetuated by making the game principle intuitive and simple and the degree of difficulty well-balanced, i.e., challenging but not frustrating.

E) Ratio of leadership & freedom: Concerning their actions the players are content with the experienced mixture of leading and freedom.

To obtain the right mixture of leading and freedom the story shall not be completely free developable but can deviate from a core story within certain limits. Therewith is also achieved that players do not lose track of the goal of the game.

Furthermore the leading shall happen by a game controlled guide that appears as character of the story in the game.

After the end of this project a case study that uses the exemplary implementation of the new game concept will enable me to judge if the project aims could have been achieved and allow answering the raised questions.

Those who shall benefit from the results of the present Master‟s thesis are predominantly players of primarily narrative games who also attach importance to flexible, interactive plots. In the second instance, the field of Interactive Storytelling shall profit from this Master‟s thesis since this research work is meant to make a scientifically valuable, useful new contribution to it.

1.3 Project Intention

This section shall give an overview of this research project on Interactive Storytelling for multiple players. Starting from the new game concept described in short in 1.1 the intention of my research project will be portrayed now. The realisation of the intention shall result in the achievement of the aims described in the previous section.

First, after examining the start of the art in the field of Interactive Storytelling and checking the eligibility of the new game concept, I will analyse the two major problems that evolve from the new game concept and trace them back to their causes. For these problems I will develop different approaches that have the potential to solve them. On the basis of these approaches I will develop a detailed and complete game concept representing an interactive drama for multiple players. Thereby I will discuss diverse possibilities, further raised minor difficulties and alternatives concerning the realisation of Interactive Storytelling.

In the following I will define criteria that are meant to allow a critical evaluation of the quality, the abilities and the success potential of the developed concept. These evaluation criteria will be of qualitative nature, thus not measurable. To ensure expressiveness of the criteria each criterion shall evolve from an aspect of the developed game concept.

Thereupon a requirements analysis will help me to determine the demands of the concept on an adequate concept realisation. It shall clarify the necessary functions and restrictions of the game software in general, as well as examine how the implementation has to look like in particular since the implementation shall be adapted to the intended case study.

On the basis of the analysed requirements the suitable software architecture needs to be sketched providing a basic structure for the following actual, running implementation. This specific implementation is going to not only be fully adapted to the game concept but also to take in account the restrictions and demands that a case study rises. Thus first of all a variable game story needs to be generated suiting all aspects of the developed game concept.

Last but not least part of the intention is represented by a small case study. This experiment firstly needs to be designed. Next I will develop a questionnaire on the basis of the defined evaluation criteria. After the following execution of the experiment with unbiased real human players the questionnaire is being used to get to know the opinion the players concerning the new gaming principle. Additionally the players shall be observed while playing in order to confirm their answer from the interview. The statements of the participants shall then been drawn on to a specific evaluation of the experiment results and a critical general judgement of case study itself.

Finally the results of the case study shall provide me with the information required to answer the questions the new game concept raised. At the end I will be able to judge the success or the failure of this research project and to justify the respective result.

CHAPTER 2:
Fundamentals

Within this chapter I will present the general and specific basics of the involved research fields necessary to understand my motivations and my work described later in chapter 3. Also an insight in relative works will be given.

2.1 Fundamentals of Multiplayer Gaming

Since multiplayer gaming will be an important aspect of the new game concept the following section provides information about customary techniques of multiplayer-playability in computer games. How can the multiplayer ability be realised, which realisation is used for which kind of games, and is one of those suitable for my needs?

Generally in the field of computer games Multiplayer Gaming means playing with or against other real persons. Apparently there are three possibilities where the cooperating or competing players can sojourn: firstly, all together at the same physical place sharing the same computer and screen via multiple separate input devices (A in Figure 2-1), secondly all at the same place using their own computer, screen and input device (B in Figure 2-1)and thirdly each player at a different physical place (not more than one player in a room) using his own computer, screen and input device (C in Figure 2-1)) whereas for the both last options their computers communicate via a network/ internet (cf.). Thereby the choice of the setup depends on the multiplayer game itself, and sometimes more than one of these are available within a game.

All three multiplayer variants contain a lot of similarities but also entail differences that noteworthy influence the gaming with or against each other. What do they have in common? Independent of where the players are located three aspects of multiplayer gaming can be ascertained: on the one hand the underlying

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Figure 2-1 Types of Player-Computer- Room setting (in the example of four players) Green represents the players, blue a computer (screen).

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Figure 2-2 Screenshot of Quake II showing a four players – split-screen

Each player has an own view on the game.

© id software 1996

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Figure 2-3 Four Wii Sports players sharing one non-split screen

The game screen is visible in the upper right corner. The players have the same view on the game.

© Nintendo 2006

shared social gaming experience with other (real) people is very attractive; on the other hand players are attracted by the opportunity of comparing their personal performances. Furthermore, disadvantages of computer simulated co-players like unrealistic and simple behaviour do not lessen the game fun.

What distinguishes them and wherein do their differences result? Multiple players playing together at the same computer often share a single screen whereas using separate, own input devices. In case due to the played game each player needs his own, independent acting-perspective of the game the obvious solution is represented by a split-screen (see Figure 2-2) dividing the screen into two or more areas – one for each player^[8]. Yet this possibility limits the number of players since the screen shouldn‟t be divided more than four times for the sake of clarity and size of each perspective. A common perspective is required if due to the kind of game the screen or rather the game scene displays all players together which results in a smaller view on the played character and the game environment (see

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Figure 2-4 Screenshot of multiple players in the MMORPG World of WarCraft

© Blizzard Entertainment 2005

Figure 2-3) (compared to single-player games). Above all one the hand the number of players is quite small due to the limited space in front of a usual screen; on the other hand these players mostly know each other personally.

In Multiplayer Online Games the players do not have to be in the same “real” room and each player uses his own computer and screen unshared. The game runs on a central server in a network and handles the displaying of the game on the clients. (A mixed variant is represented by “LAN-parties”: many players using their own computer but the same physical place.) However, this kind of multiplayer gaming mostly requires a communication possibility between the players that is being realised by chats or VoIP. Also the internet-players often do not know each other in real life which seems to be quite popular since they can get to know people from counties all over the world enabling them to make new, far- off friends. Additionally, the numbers of players is not limited. This freedom resulted in the currently highly popular MMORPGs (see Figure 2-4).

Meanwhile multiplayer modes can be found in a several different game genres such as the mentioned MMORPGs^[9], First-person shooters^[10], Real-time strategies^[11] or Electronic sports^[12]. (Evidently the genre of Adventure is yet not being represented!)

The new game concept shall be a pure multiplayer game. That means I need to decide on the type of setting which I consider as most suitable for the game concept. This includes the location of the players, shared screen or separate screens, the players‟ view on the game and the kind of communication between them. In the chapter 3 I will present my decision.

2.2 Fundamentals of Adventure Games

Another aspect is the classification of the new game concept into the computer game genre of Adventures due to its narrative game principle being the focus of the game. This section shall serve the purpose of dealing with some of the relevant subjects of this genre since they will be part of the new game concept.

Generally Adventures are distinguished from other game genres by a story of which the plot is to be unfolded by the player. They have a well defined beginning (“exposition”) and one or sometimes more endings (“denouements”) that are to be reached by the player by gaining information, talking to game controlled characters, finding items and solving riddles.

Aside from that, Adventures (in the classical, “traditional” sense, i.e., excluding Role-Playing Games, Multi User Dungeons, Action-Adventures etc.) are single player games. All characters apart from the one of the player are NPCs that are exclusively controlled by the game but can be interacted with by the player character.

An outstanding, often discussed and complicated aspect of Adventures is the matter of linearity. In the field of narrative gaming there is no explicit, consistent definition of what makes a plot linear or non-linear. Since the available explanations are too weak for my needs I prefer to explain my understanding of plot linearity separately.

To each Adventure a plot graph^[13] with a fixed structure can be assigned.

The emerging story of the game arises from the one taken path through this graph. Due to this circumstance I want to mark out that, considered strictly, linear Adventures can actually not exist. As soon as the plot branches – which is the case in every Adventure (where do I let my character go first, etc.) – it cannot be purely linear anymore. Basically, truly linear plots only exist in books, movies, etc. since they offer no plot alternatives (see Figure 2-7 on p. 15).

Nonetheless the linearity of Adventures is often discussed (for example in an interview with the game designers Wolfgang Kierdorf & Martin Lassahn – see [KierLass05]) or in many cases often a factor in the appraisal of Adventure games. But what from my point of view is mostly meant when speaking of a

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Figure 2-5 Screenshot of the player’s decision point in I ndiana Jones and the Fate of Atlantis Choice between Wits Path”: more difficult, “Fists

Path”: lighter puzzles and lots of fights, or “Team Path”: easier due to support of a NPC.

© LucasArts 1992

linear plot design is the non-variability of the order of solving riddles and of the way of solving tasks. That is, the order of key points is fixed, with key points being user decision points that advance the development of the story (for example solving a riddle but not going to the left).

If now accepting the latter meaning then Adventures cannot simply be classified as fully linear or non-linear; it would be more sensible to speak of their degree of linearity since most of them (if not all) are rather partly linear than totally or not at all^[14]. (If considered strictly, linear parts can only be parts of no user interaction, for example cut scenes etc.) Therewith an Adventure can be mostly linear until short before the end when the player‟s acting decision results in one of the multiple available endings. Such a decision can certainly alter the further story at any point in time of the game (cf. Figure 2-5) but not necessarily has to.

To summarise, the player‟s degree of freedom in action is what separates linear and non-linear parts of the plot – his actions push forward the story and can but not necessarily have to alter the story (the pure pushing forward I call “weak narrative consequence”) (cf. Figure 2-7).

Which effects does a linear plot have then? If compared, the linear parts push the plot whereas the non-linear parts convey the feeling of gaming freedom to the player. Coming back to the aspects of the narrative structure of Adventures, then from a game designer‟s point of view a linear design is less complex but easier enables establishing a dense dramatic arc (cf. Figure 1-3 on p. 5) and furthermore results in rather a film than a game. On the other side complex a non- linear plot creates a wide scope of player actions that yet makes it more difficult to establish a dense, self-contained story dramaturgy. Thereby a too strong linearity can discourage the player whereas a too weak linearity could intimidate him [KierLass05].

Since the just mentioned dramatic art is a very important aspect of the new game concept I will go into this subject in the following. The characteristic of the emerging story is the underlying narrative structure that is known from, for example, tales or movies: the dramatic arc. This claim makes the designing of Adventures interdisciplinary: designers of narrative games must consider the rules of game design as well as the rules of dramatic narration – a nontrivial challenge since both are already on their own not simply to be mastered. The purpose of following the dramatic arc in narrative games is just the same as for any other narration: namely, making the story enthralling and entertaining, that is, motivating the recipient of the story to get to its end.

But how can the dramatic art of game stories be ensured? Herein the degree of linearity plays an important role for it is easier to make the story of a mostly linear plot dramatic than of a rather non-linear one. The reason is the increase of the variety of the story events with the increase of the non-linearity. Since the order of story events is predefined and fixed in for the most part linear plots, the game designer is able to map certain story events to certain parts of the dramatic arc. For example, he may map a story event which is in the middle of the plot to the climax of the dramatic arc by designing this event as a large conflict. However, in a non-linear Adventure the action sequence is at many stations of the plot variable – the player-dependent path through the graph traverses only some of the graph nodes. In spite of these variations the game designer must guarantee

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Figure 2-6

Schematic graphic of the mapping of the dramatic arc onto a partly non-linear

(A) and fully non-linear plot graph (B)

The blue nodes refer to “stations” (A) or “sections” (B) which mirror important parts of the (simplified) dramatic arc (in brown).

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Figure 2-7 Plot linearity and plot structure (considered strictly) (The grey text is not valid for classical Adventures.)

that the player reaches the climax, independent of which action decisions the player makes. To achieve this there are two possibilities: firstly, integrating stations in an otherwise non-linear plot (that therewith is being interrupted by linear parts) where all previous strands run together (see A in Figure 2-6., and secondly, a complete non-linear plot that is divided into sections according to the respective parts of the dramatic arc (see B in Figure 2-6). One section contains for example multiple conflicts of which one the player passes for sure. This second solution is more complicated and time-consuming; moreover the player is not able notice the difference except he plays again and acts different from before.

Which plot type is the suitable one for the new game concept? This question will be answered in chapter 3.

2.3 Fundamentals of Interactive Storytelling

As the title of the thesis already reveals Interactive Storytelling is an important part of the new game concept and shall be examined in short now. I will give a brief terminological introduction into this field and an insight into the known corresponding problems since the new game concept will strongly be confronted with them.

The research field of Interactive Storytelling is rapidly developing, and since its emergence many people - game designers as well as research groups - have dealt with the central question: What in special makes a story interactive?

To answer this question I consulted a large amount of respective literature but I was not able to find a unified statement since the opinions widely diverge. (e.g., [Chrawf04], [Mateas02], [Meadows03], [Miller04], [Mosel05], [Sander06], [Szilas99], [RieYou05], [Ryan01] and [Trogem02]). Due to this circumstance I will define Interactive Storytelling myself, in fact, in consideration of the new multiplayer game concept. I consider an interactive story as story of which the development is being altered by the watcher/ listener/ reader/ player (from now on “recipients”), even if this influence is only small. Therefore an interactive story cannot be unchanging; what is variable is its degree of interactivity. For example some Adventures offer different story endings whereas the rest of the story is not alterable by the player – this represents little interactivity; different from gamebooks, which provide the reader with several opportunities of affecting the further development of the story between its beginning and end. Thereby the following must be pointed out (specified for digital games): in most cases of story interaction the player can only choose from a limited and rather small number of story development possibilities rather than freely determine it. In this case he rather appears as director than author, that is, author is the game designer who provides an automatic telling of the story. For this purpose the plot structure needs to be predefined and fixed which means that all plot graph nodes (cf. previous section) and all the connections between them cannot be changed by the player. To allow the player the appearance as author (the plot structure would have to be flexible and open) he must be given free authoring possibilities – quite easy to realise in interactive theatre, basically impossible for gamebooks, and difficult but

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Figure 2-8

Connectivity of plot linearity and story interactivity (strict)

The blue text shows the areas of Interactive Storytelling.

possible for narrative computer games (namely in form of authoring tools).

Concerning Adventures with a directing player I see two “layers” in the unfolding story: firstly the background story or core story; secondly the filling, rather weak narrative part of a story. The consequences of the player‟s decisions can – depending on his degree of freedom of action – either alter only the weak layer or both layers: solving which riddle when would not alter the background story but only push it forward; deciding to take the money or rescue the princess alters the background story itself. A truly interactive drama must provide strong narrative acting consequences while at the same time provide the classical narrative structure like fairy tales or movies! (cf. Figure 2-8)

I will now come to the central difficulty of Interactive Storytelling since I will have to deal with myself. As soon as a story becomes interactive the author has not any more full control over its course. Depending on the degree of the given influence on the story development a dramaturgical problem evolves. The central difficulty of designing an Interactive Drama has been formulated best by Knut Hartmann: the combining of dramatic storytelling and player interactivity. Thereby attention needs to be paid to the two following contrary requirements: on the one hand a well-balanced and dramatic plot is essential for a successful story and on the other hand giving the player multifarious interaction opportunities in such a way that his actions noticeably influence the advance of the plot by. [Hartm07] Diverse research groups have developed approaches that move away from fixed plot structures and enable total new game concepts. P. Bailey divided previous works on automatic storytelling in these three groups: “author models”, “story models” and “world models” [Bailey1999]. I will not go into these approaches but instead provide an overview of different types of plot structures since I have to decide on an appropriate plot structure for the new game concept.

The diagrams Figure 2-9 to Figure 2-11 on the next page are some examples on interactive narrative plot structures and shall deliver a small, comparative insight into their attributes, qualities and application. Their plot structures are divided into nodal, modulated and open. In Table 2-1 on page 19 I compare these three types of plot structures with regard of design, dramatic art and their degree of interactivity.

Which type of plot structure will be the most suitable for the new game concept I will explain in chapter 3.

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Figure 2-9

Example for a Nodal Plot Structure

© M. St. Meadows 2003

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Figure 2-10

Example for a Modulated Plot Structures

© M. St. Meadows 2003

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Figure 2-11

Example for an Open Plot Structures

© M. St. Meadows 2003

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Table 2-1

Comparison of the three types of plot structures

Source: [Meadows03]

2.4 Related Works

In the chapter Introduction I described which open questions the new game concept brought up. In this section I will examine if similar approaches are able to answer the central question, namely, if Interactive Storytelling works for not only single but also multiple players. The following exemplary selection shows games which bear the most resemblance with the new game concept.

In the year 1999 an interactive drama for children appeared on the market: Schneewittchen und die sieben Hänsel (in English: Snow-white and the seven Hansel) developed by Tivola Verlag GmbH, Berlin (cf. Figure 2-12 on the page). The particular matter about this game is the plot: crossing strands that base on three well-known stories: the fairy tales of the Brothers Grimm, Snow White,

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Figure 2-12

Screenshot of Schneewittchen und die sieben Hänsel

The player is asked to decide on the walking direction of the actually played character.

© Tivola Verlag GmbH 1999

Little Red Riding Hood and Hansel and Gretel^[17]. Apart from that this game is a quite classical Adventure, using classical 2D graphics. The stories are being automatically generated and are told in sequences of each with ten pictures. A large number of hotspots in each picture that result in speech, animations, music and sounds make the game be intensively experienced and integrate the young player into the events and bind him emotionally. Also, the game allows reaching a number of “false ends”; right ends are reached when telling the tales traditionally correct by making the suitable decisions. The specialty about this game is the aspect that the player controls three instead of usually one character, and that these player characters (and therewith the player) are being accompanied by three NPCs in order to provide the player with the feeling of not being alone. The underlying implementation is not public; yet it is know that the dramatic structure is being ensured by a fixed, mostly non-linear plot structure with a rather small number of alternatives. The story is interactive since the player‟s decisions result in a respectively different development of the unfolding story. (cf. [Kolloff00])

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^[1] The first Adventures were text Adventures, i.e. visible to the player was only text that told the

^[2] Done in the Adventure Indiana Jones and the Fate of Atlantis, published in 1992 by LucasArts: In the middle of the game the player has to choose between an aggressive, diplomatic or team- based behaviour of his character. Before and afterwards the main story is hardly influenceable.

^[3] The first commercial interactive drama was Dragons’s Lair, published in 1983 by Advanced Microcomputer Systems. It contained just a single successful storyline; the interactivity based on making the right (successful) decisions - false player decisions resulted in the presentation of a death-scene.

^[4] For example Fahrenheit (also named Indigo Prophecy), published in 2005 and developed by Quantic Dream, or Deus Ex, published in 200 and developed by Ion Storm.

^[5] For example World of Warcraft, published in 2004 and developed by Blizzard Entertainment.

^[6] According to Aristotle's Poetics, a plot is "the arrangement of incidents" that (ideally) each follow plausibly from the other. He divided it in three parts: beginning, middle and end. [ArisBC]

^[7] The Dramatic Arc: Good drama is built on conflict of some kind - an opposition of forces or desires that must be resolved by the end of the story. [Quince07]

^[8] Round-based gaming could be another solution but were a strongly unsatisfying one nowadays since only one player could be active while the others had to wait until their turn.

^[9] Popular MMORPGs are Ultima Online (Origin Systems 1997) and World of Warcraft (Blizzard Entertainment 2005).

^[10] Exemplary First-person shooters are Unreal Tournament (Epic Games 1999) and Quake 3 Arena (id software 2000).

^[11] Typical Real-time strategies are The Settlers 1-5 (Blue Byte Software, from 1993 on) and WarCraft 3 (Blizzard Entertainment 2002).

^[12] The EA Sports series contain a lot of sport games, e.g. UEFA Champions League 2006-2007 and NBA Live 07.

^[13] Meant is the graph from the graph theory: a geometric set of nodes that are connected by edges. The nodes of a plot graph represent scenes; the story is one path along its lines. The plot itself is therewith a sequence of story events.

^[14] An example for an Adventure with a larger degree of linearity is Broken Sword: The Shadow of the Templars (Revolution Software 1996) due to the little variety of the order of solving riddles and visiting places. A rather little linear Adventure is Indiana Jones and the Last Crusade (LucasArts 1989). It contains the “indy quotient”, of which the maximum points can only be reached if all riddles are solved and all solution methods were taken, in fact only by playing more than once.

^[15] Deus Ex, developed by Ion Storm in 2000, combines action elements of an ego-shooter with the character development of a role-playing-game and the story of an Adventure.

^[16] The Memex Engine is an interactive installation by Marc Lafia.

^[17] All three tales have been published by the Grimm Brothers in the German fairy tales collection Kinder- und Hausmärchen (Grimm's Fairy Tales) in 1812.