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#Post#: 62--------------------------------------------------
Foundations of Interactive Storytelling
DIR By: Pam
Date: May 30, 2021, 7:02 pm
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Based upon the presentation 'Interactive Storytelling in Games:
What it is, Why we need it, and How you do it' presented by
International Hobo at Digital Media World 2001, November 13th
2001. Source: IGDA
HTML http://web.archive.org/web/20050207022423/https://www.igda.org/writing/InteractiveStorytelling.htm
Stories have most likely been part of the human experience from
the earliest days of language, but until recently the
storytelling medium has been largely static. Barring different
versions of the same story, any given tale unfolds the same way
every time one reads it. Computer games promise the potential to
move beyond this strictly linear form by offering stories that
interact with the player, allowing them to participate in the
decisions or actions that shape the narrative. However, at the
current time this field is still in its infancy.
The origin of interactive storytelling probably dates back to
Tactical Studies Rules Dungeons & Dragons (1974), itself based
upon a set of tabletop battle rules - Guidon Games' Chainmail
(1971). Similar in terms of mechanics, Dungeons & Dragons had a
revolution in its focus, changing the game play to being about
characters, not armies. This was the start of tabletop role
playing games (RPGs), which were to influence and inspire many
computer games to follow.
The tabletop RPG is a 'perfect' interactive storytelling medium,
as an unrestricted story develops from the dynamics of the group
of players, led by a Games Master (GM). The former decide upon
the actions of key characters in the story, the latter takes the
role of the rest of the universe - becoming very much the
surrogate author of the collaborative tale that develops.
In many ways, the quest for interactive storytelling in games is
a quest towards the perfect state that tabletop RPGs already
had. The computer game takes the role of the Games Master, and
the players remain in control of the lead character's (or
characters') actions. The problem is that a human GM can respond
to any conceived action on the part of the player, but until
Artificial Intelligence advances an astonishing degree, computer
games are inherently limited in their flexibility.
What computer games lose in terms of the freedom offered in
tabletop RPGs, they make up for in immersion. Any tabletop RPG
game is still essentially a group of people developing a dynamic
story through words alone - a computer game provides the visual
and aural experience that brings it closer to cinema than radio
theatre (which is the medium that tabletop RPGs arguably
resemble most strongly). This difference in the size of the
audience for film compared to radio plays is reflected in the
difference in audience for tabletop RPGs versus computer games.
This essay looks at the foundations of interactive storytelling,
with a focus on their relevance to computer games. Tabletop RPGs
(and the related medium of adventure gamebooks) are an important
part of the background and history of this new medium, but will
forever by a minority pursuit. Computer games, on the other
hand, look set to take the reigns of interactive storytelling
and bring them to a broad, diverse and expectant audience.
#Post#: 63--------------------------------------------------
Re: Foundations of Interactive Storytelling
DIR By: Pam
Date: May 31, 2021, 4:34 am
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Defining Interactivity
What is it we refer to when we talk about that which is
'interactive'? Although this may seem trivial, language is
seldom a solid foundation for discussion without some definition
of terms, and choosing what we mean by 'interactive' and
'interactive storytelling' can only serve to clarify the scope
of this essay.
Reactive
We can define 'reactive' as "responding to some influence or
input." That which is reactive is associated with a flow of
information in one direction. Television is a reactive media:
you can only watch (react) to the information it provides.
[center]
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You cannot (at least not prior to the recent introduction of
interactive television shows e.g. Endemol's Big Brother series)
influence the events that you are watching.
Interactive
We can define 'interactive' as "reciprocally active; acting upon
or influencing each other; allowing a two way flow of
information." Every computer game is inherently interactive,
since the player performs certain activities, sees them occur in
the game world, and then adapts their actions to reflect the
results in the game world. There is an exchange of information
between the player and the game which is bi-directional.
There are numerous degrees of interactivity, however, and as
computer games have advanced, we have seen advances in the
degree of interaction.
[center]
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From an initial state where control is the only interactive
aspect, e.g. Nutting & Associates' Computer Space (1971) or
Atari's Pong (1972), we have seen interactive levels of ability
(i.e. power ups) with Midway's Pac-Man (1980), interactive
environments with Universal's Mr. Do (1982) and so forth.
Understanding the distinction between reactive and interactive
media is the first step towards understanding what can
meaningfully considered an interactive story.
#Post#: 64--------------------------------------------------
Re: Foundations of Interactive Storytelling
DIR By: Pam
Date: May 31, 2021, 4:37 am
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Interactive Stories
Any game featuring both characters and a story in which one or
more narrative aspects changes interactively can be considered
an interactive story. The possible narrative aspects that could
be made interactive include:
Plot
The most obvious route to interactive storytelling is by
creating a plot that varies in response to the player's actions.
Perfect Entertainment's Discworld Noir and (to a much lesser
extent) Konami's Metal Gear Solid are examples of this.
Character attitudes & personality
A more satisfying way to approach interactive stories is to look
at ways that the player's actions might affect the attitudes of
characters in the game world. We will look at several ways of
approaching this later in this essay.
Theme
Although strictly hypothetical at this time, it is possible to
conceive of a game in which the theme varies interactively. For
example, we can imagine a game in which the story elements are
mediated by the game's story engine in relation to that which
the player has paid the most attention. If the player spent
considerable time talking to a romantic interest, the theme of
the story becomes biased towards a romantic element; if they
focussed on violent activity, the thematic details might evolve
around an exploration of violence.
Mastering dynamic plots and character attitudes will almost
certainly be a prerequisite to exploring interactive themes.
Note that our definition requires more than both interactivity
and narrative elements to be both present: many computer games
(which are inherently interactive) have story elements, but that
does not make them interactive stories. Only if the form of the
story itself is interactive can we seriously make a claim to it
being an interactive story.
#Post#: 65--------------------------------------------------
Re: Foundations of Interactive Storytelling
DIR By: Pam
Date: May 31, 2021, 4:40 am
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The Value of Interactive Storytelling
Now we have defined what can be considered an interactive story,
we are in a position to discuss why interactive storytelling
might be of value - both artistically and commercially. Just
because a thing can be done does not make it worth pursuing, and
with the medium in its current, nascent form it is necessary to
make a case for its importance.
From an artistic perspective, interactive storytelling
represents a new, highly expressive art form. Before the 20th
century, all art was essentially reactive. A work of art was
created, and it created an emotional (or intellectual)
experience in its audience. Interactive art creates a dialogue
between the art and the audience, creating a more immersive
artistic experience.
This issue of immersion is linked to the commercial appeal of
interactive storytelling. Many games satisfy the player's need
for a sense of involvement in the story by creating the illusion
of an interactive story. Either the game forces the player to
jump through certain story-based hoops in order to progress,
e.g. Sega's Shenmue series, or the game features a gameplay
element wholly separate from the narrative, as is seen in
Square's Final Fantasy series in which the player is engaged in
largely pointless combat between story elements. In both cases,
however, the players actions have essentially no effect on the
progression of the story. When executed subtly, this illusion
can be quite effective; often, however, players are left asking
"why can't I do that?" or worse "why do I have to do that?"
Providing a true interactive storytelling experience has the
potential to satisfy the audience by connecting their actions to
the unfolding story directly. This may be as simple as
reflecting the player's actions in dialogue, or as complex as
dynamically varying the sequence of events to work around the
player's choices. Either way, this non-linearity appeals to the
hardcore gamers (including the majority of magazine reviewers)
offering a direct commercial advantage. It also implies a
greater replay value, as hardcore players replay the game to see
the other ways the story could have transpired.
Of even greater commercial value is the potential to unlock a
vast reservoir of casual gamers already circling at the fringes
of the games medium. The casual gamer lacks the patience (or
stubbornness) to persevere with a game that annoys them, but
once hooked in become intensely loyal to those games that have
grabbed them. As with television and film, there are few better
ways to captivate than with interesting characters and plots.
However, the viewer expects no control of the outcome in the
former media - in games, control of the flow of events is
expected, but is usually illusory. Games with relatively
easy-to-play game space, but an interesting dynamic story space
have the potential to dramatically expand the size of the
computer game audience.
#Post#: 66--------------------------------------------------
Re: Foundations of Interactive Storytelling
DIR By: Pam
Date: May 31, 2021, 4:52 am
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Interactive Plots & Non-linearity
The term 'interactive plot' can be taken to be broadly
synonymous with the terms 'non-linear story' or 'non-linear
plot'. The term 'non-linear' is self-explanatory, but in this
context should be taken to mean that the story elements
(dialogue with other characters, cut scenes et al) do not occur
in a fixed sequence. There is a wide range of extents to which
this non-linearity can manifest in a game story. Note also that
a game can be non-linear and yet still have a fixed outcome -
the issue is the journey through the plot, not its conclusion.
The structure of a game's story determines wholly the extent of
its non-linearity, and there are various degrees of
interactivity of plot that can be expressed.
Linear
The most basic structure imaginable is linear: the game's story
elements unfold in a strictly linear sequence. Sometimes the
game play will be non-linear, but the game elements can unfold
in a non-linear way. This is true of many games at the moment:
the story proceeds as a series of linear checkpoints that the
player reaches in sequence, although they may have freedom to
explore the game world in a broadly non-linear fashion.
We can visualise the linear structure as a straight line:
The advantages of the linear structure are that it is a reliable
and resource-cheap way of approaching the story.
[center]
HTML http://web.archive.org/web/20050214081027im_/http://www.igda.org/writing/images/IS_03.gif[/center]
In games with a low budget, the linear structure is often the
only affordable approach.
The disadvantages are obvious: it is unimaginative, and the
player has no control over the development of the plot. If the
game successfully manipulates the player into caring about the
same issues as the characters, the disadvantages are minimised -
but if the player ever feels trapped in someone else's story,
the linear structure is usually to blame.
Branching
The branching structure is rarely used, and for good reason. The
branching structure leads to a number of fatal problems, and
indeed is in part responsible for the miscomprehension that
non-linear stories are intractable or inappropriate for use in
games. It is unfortunate that many people in the games industry
believe that the branching structure is the only non-linear
option available, and this may be in part the reason for the
persistence of the linear structure.
We can visualise the branching structure as a tree:
[center]
HTML http://web.archive.org/web/20090727161428im_/http://www.igda.org/writing/images/IS_04.gif[/center]
The plot begins at the base node, and certain points in the
story are defined as branch points, where the plot splits into
separate paths. With no recombination of threads, the branching
structure leads to a number of end points equal to the number of
branch points plus one (for two-way branching) or even more (for
multi-path branching).
The fact that the number of end points is so huge is what is
known as the combinatorial explosion. Branch in two ways four
times and you have to deal with sixteen different paths (24 =
16) - and each binary branch point that you add to all paths
doubles the total number of outcomes. No game could survive such
a vast investment in potentially unused resources, and as a
result the branching structure (when it does appear) is usually
pitifully simple (often just a single branch point).
Parallel Paths
The parallel path approach (which could also be considered a
fully recombined branching structure) is a tenable and useful
approach to story design, used to some extent in games such as
Konami's Metal Gear Solid (1998), and Ion Storm's Deus Ex
(2000). Branches recombine at the key story points, creating a
structure which is a balance between linear and branching
structure:
In the following diagram, those story points which have a green
line through them are branch points splitting into three routes
- but those paths then recombine before the next main story
point. The underlying structure is linear:
[center]
HTML http://web.archive.org/web/20090727161431im_/http://www.igda.org/writing/images/IS_05.gif[/center]
every player must through every point on the spine of the story,
but there is still some freedom as to how the player reaches the
next point.
Metal Gear Solid, whilst essentially a linear game, features a
single segment of parallel path structure which does much to
improve the player's involvement in the game's story. This
sequence, in which the player is tortured repeatedly but has an
opportunity to escape between the torture sessions, has three
paths through it: the player escape in a couple of different
ways from the cell between torture scenes, they may admit defeat
to the torturer, or if all else fails, they are eventually
rescued from the cell by a deus ex machina. This parallel path
segment also governs a split in the games ending: if the player
does not give up in the torture scenes, they will end up
rescuing the romantic interest - but if they do, she is killed
and the player ends up escaping with a buddy character instead.
Although simplistic, this remains a strong example of the power
of even a basic non-linear structure, giving the player a
genuine moral decision to face with consequences within the
framework of the story.
This example also typifies the needs of the parallel path
structure's branch points: a primary path (rescue the romantic
interest), a secondary path (escape with the buddy character)
and a catch-all tertiary path (the player is rescued) to ensure
that the plot will move forward whatever happens. In point of
fact, this sequence from Metal Gear Solid is two separate
branches (resist torture, or give up is the first branch; escape
on their own, or be rescued is the second branch) leading in
effect to four different paths through this sequence, ignoring
the issue of the means by which the player may escape by their
own means. Only the first branch is expressed in the development
of the rest of the plot, however, and in the branch at the end
of the story.
The disadvantage of the parallel path structure is that more is
developed for the game than is actually seen. As soon as you
have two endings, only players who play the game twice will have
any hope of seeing all of the story material, although this
disadvantage is offset if it is expected that most players will
replay the game (i.e. the game is both short and fun).
The advantage lies in the choices the player has within the
plot, and the sense of connectivity with the story that is
engendered. Every time a game gives the player a meaningful
choice, the become more emotionally involved with the story -
although of course this may only be effective if the player
knows they had a genuine choice. Because many players do not
expect to be given a meaningful choice, sometimes the player
will play along with what they believe is expected of them,
because their prior experience of games has given them no reason
to believe that they are facing a genuine decision. It is
important, therefore, to ensure that the player is subtly taught
or informed that their actions will affect the outcome, if this
is in fact the case.
Threaded
The threaded structure is a powerful, complex way of allowing
the player a non-linear story experience. Games such as Perfect
Entertainment's Discworld Noir (1999) use a threaded structure
to give the player a genuine degree of freedom to explore the
story space once the initial formalities of establishing
setting, character and interface have been concluded.
The following diagram is an approximation of the structure of
Discworld Noir's first two Acts:
[center]
HTML http://web.archive.org/web/20090727161429im_/http://www.igda.org/writing/images/IS_06.gif[/center]
Unlike previous diagrams, the course of the plot does not follow
a single path in this form of structure. Rather, the story is
comprised of a number of different threads that develop largely
independently (at least until the closing stages of the story).
This parallels the methods that quality novels and films employ
to develop the plot, with multiple narrative threads being woven
together to produce a satisfying story.
The key to the symbols employed is as follows:
- Yellow circles represent the events at the start of an Act.
Every Act starts in the same way in this particular example of
the threaded structure, although this is not a given.
- Blue circles represent non-mandatory plot events.
- Red circles represent mandatory plot events: the player must
experience all red circles (and must experience at least one
circle with a black centre) to proceed to the next Act.
- Red lines show Act boundaries.
- Green lines show the places at which threads connect to one
another (the places at which new threads are 'unlocked').
For example, starting at the beginning of Act I (the bottom
yellow circle), the player is introduced to some back story and
placed in the role of a private investigator in a fantasy world.
They begin their investigations and soon reaches a point at
which they are investigating multiple cases (the green line
opens up two other threads, one to the left and one to the
right). The player can eventually conclude the first stages of
their initial investigation in two different ways (the red
circles with black centres), but they may also begin
investigating two other (apparently) separate cases (the path to
the left and the path to the right). The right-hand thread
represents the true conspiracy the player is investigating, and
by the end of the first act, the player has already changed
their conception of what is going on twice (signified by
successive jumps along green lines).
The left hand path (which represents a side-story concerning a
missing dwarf) shows an optional side path in which the player
may investigate the case to a certain extent in the first Act,
but cannot conclude it until the second Act. This case can also
be largely side-stepped, as another chain of events in the
second Act will eventually connect with the details of this case
allowing it to be ignored - at least until it closes in on its
terminal red circle which is an essential part of the plot.
Although this system is highly expressive, and leads to a
freedom of movement within the story space which is uncommon,
there are several problems which makes this approach of limited
future value. Firstly, tracking changes in the plot skeleton
during development is nightmarishly difficult: because of the
sense of interconnectivity between events, it is very hard to
implement structural changes. Furthermore, the complexity of the
plot skeleton means that very few members of the development
team will fully understand the structure. Given how difficult it
is to fully appreciate a diagram showing a simplified version of
the structure, it is easy to see why dealing with this structure
in practice is no small undertaking.
Additionally, the degree of variance in the story structure
makes QA much harder to perform completely (especially if there
is no way to educate the QA team on the full extent of the
underlying plot structure) which can lead to an extended QA
period being required to ensure the stability of the code.
Of course, these problems are offset by the highly expressive
nature of the structure, and the number of options for player
freedom within the story. Unfortunately, much as with the
parallel path structure, a great deal of this is lost on players
if they do not realise that the freedom exists. Unlike the
parallel path structure, however, the threaded structure has an
ace up its sleeve: with so many routes through the plot
supported, the player may not recognise the non-linear nature of
the story, but they find that the game supports a fair degree of
the actions they want to perform within the plot, which aids
immersion. In essence, the advantage comes in the player not
being blocked in their attempts to experiment - they are never
faced with the inevitability of conforming to a linear plot (at
least until the threads begin to recombine prior to the ending).
Nonetheless, what we really desire for interactive plots is a
system as expressive as a threaded structure but as robust as
parallel path structure.
Dynamic Object Oriented Narrative
A possible future of interactive plots is suggested by systems
for dynamic object oriented narrative such as International
Hobo's FreeSpeak. These use a notion from computer science (that
of object orientation) with the framework used in commercial
television series to provide structures that are even more
expressive than the threaded structure, yet as robust as a
parallel path structure.
The following diagram shows a hypothetical object oriented plot
skeleton:
[center]
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Before discussing the illustration, the idea of 'object
orientation' must be approached. Simply put, object orientation
concerns dealing with a problem by composing the data space from
objects, which contain other objects, which contain other
objects (like quarks in hadrons in atoms in molecules in bigger
things). Everything is composed of small functional components,
except for the atomic units at the base of the chain. The idea
revolutionised programming languages in the 1980's, and may be
about to do the same for interactive storytelling.
In the above diagram, blue squares represent an object known as
an Episode (small blue squares indicate Episodes not covered in
this example diagram), while all circles represent a Scene. Each
episode consists of a number of Scenes which can use any
structure - linear, branching, parallel path etc. Because each
Episode is comprised of a small number of Scenes, the resulting
set-up is robust and connectivity can be tracked on two
different levels: transitions between the Scenes of an Episode
(blue lines), and transitions between Episodes (red arrows).
Episodes are broadly chronological, but Episodes that refer to
events that occur concurrently (i.e. that are at the same height
in the case of this diagram) can occur in any sequence. In this
particular example, the possibility of starting the story at
different 'places' in the plot is represented by yellow circles
(which might, for instance, represent playing through the story
with a different character who joins the events at a different
point).
Obviously if each Scene were a unique 'game level', this would
suffer from many of the problems associated with multiple paths:
developing many more resources than will typically be seen by
the player. This is solved in FreeSpeak by the use of various
other component entities, namely Personas (characters) and
Locations. Every Scene takes place between certain Personas in
certain Locations, and may be interactive or a cut scene. A
particular Location may be used for many different game play and
story related activities. For example, in Sega's Shenmue (2000)
the docks are used as a stage for investigation, cut scenes,
fighting, quick time events (interactive cut scenes) and even
racing (although it should be noted that this reuse of location
was performed in a linear fashion in Shenmue).
Any key gameplay that the designers wish every player to
experience can be built into the plot skeleton as an event that
must occur at some point - but the object oriented structure
allows for that point to occur at many different places within
the structure of the plot. The rest of the time the Locations
are being used as a setting for basic repetitive game play
(fighting, exploring, investigation etc.) using the core game
engine. The design of a location is thus built around its uses
in the game, but it can also be reused for story purposes.
This parallels a TV show which has a number of sets which are
reused week by week as the core places the story takes place. A
Location in FreeSpeak is analogous to a set in a TV show, with
the same advantages in terms of cost-effective reuse of
resources.
Once the initial investment in the creation of new tools, and
the corresponding skills required to operate those tools
effectively, has been overcome, the advantages manifest. The
approach promises an extremely expressive and robust approach to
interactive plots with a degree of freedom and level of replay
value (exploring different renditions of the story) which would
exceed anything we have currently seen in games.
Since its inception, developments in interactive storytelling
have been gradual to say the least, although it is quite
possible that a dynamic object oriented narrative system such as
FreeSpeak will revolutionise the approach and create a new breed
of games built around an advanced interactive plot.
#Post#: 67--------------------------------------------------
Re: Foundations of Interactive Storytelling
DIR By: Pam
Date: May 31, 2021, 12:08 pm
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Interactive Characters
The principle behind interactive characters is to model
personality in a manner which is simple and efficient. As with
interactive plots, the underlying structure tends to be
simplistic with the effect being largely illusionary, although
advances in the principles of interactive narrative promise ever
more complex representations in the future. Most games limit the
interactivity of characters to very simplistic behaviour - often
nothing more than basic, fixed conversation, but there are a
number of ways in which the players actions can be allowed to
affect the attitudes of other characters.
Note that the characters in a game may change attitudes to the
player as a result of the plot, but if the player has no control
in this change (if it is dictated as an inevitable consequence
of the story progression) it cannot be considered to be a case
of interactive characters.
Flags
The simplest implementation for dynamic personality is using
flags. A flag is a boolean variable - a type of data which can
be only true, or false. Certain player actions cause the flag to
become set (true) or unset (false) which affect the apparent
behaviour or attitudes of the non-player characters, perhaps
affecting what they say, or where they can be found in the game
world, or even whether or not they help the player.
Discworld Noir used a flag representation for some personality
behaviour; certain characters would respond differently
according to their prior conversations with the player; some
would be more or less obstructionist in their approach,
according to what the player had said to them before. The
underlying behaviour was very simplistic, however, and largely
affected only the dialogue. Nonetheless, the illusion that the
players choices were affecting character attitudes could be seen
in several places as a result of a very basic use of personality
flags.
We can explore the basic principles in a hypothetical game
drawing on the Star Wars mythos. Consider a game based around
the events of Episode IV: A New Hope, and the question of how
the finale will take place. Consider the question:
Does Han Solo bail out Luke at the Death Star?
To model the behaviour, we can look at any pivotal actions that
could occur in the game space or story space that might affect
Han's chances of coming to Luke's aid in the Death Star battle.
This might include:
- Luke and Han bond on the Millennium Falcon
- Luke rescues Han in a battle
- Luke accidentally hits Han in the foot with his light sabre
The first two flags would predispose Han to coming to Luke's
aid, whilst the third might well discourage him from bailing out
the little whiner. We would describe the logical condition that
determines whether or not Han comes to the rescue as follows:
If (Bond OR Rescue) AND NOT Sabre Then
Saves Luke
Therefore, if Luke and Han bond and Luke doesn't have a clumsy
accident while practicing his Jedi skills, he'll ride in like
the cavalry at the end. Similarly if Luke ever rescues Han, or
if there is bonding and rescuing in the early part of the story,
Luke can count on not getting his buttocks burned by Vader's
blasters. If Luke and Han never bond, and no rescue takes place,
Han doesn't feel the motivation to come and risk his life (and
his precious ship) in a rather treacherous battlezone and takes
his money to go and pay off Jabba. Similarly, if Luke gets
carried away against the remote and accidentally slices off
Han's big toe, Han isn't going to feel inclined to fly out of
the sun whatever happens and Luke will find himself facing down
his dad on his own.
The resulting behaviour isn't very complex, but the player at
least experiences some connection between what they did earlier
in the game, and how the final scenes play out.
Affinity Systems
A more complex representation than flags uses numerical values
to track the relative feelings of one character towards another.
These affinity systems (or affinity-aversion systems) were
created by game designer Paul Kidd in his tabletop role-playing
game Albedo (1988), based upon the 'Erma Felna, EDF' comic
stories by Steve Gallaci. Although the mechanics were somewhat
superfluous in tabletop RPGs (since the players and GM were
capable of making their own decisions regarding their
character's attitudes to other characters), they have proved to
have interesting applications in computer games.
Although it does not use them for player interactions with
characters, Sick Puppies' Ghost Master (2003) used an affinity
layer in its AI system for the mortals the player's ghost team
spooks and scares. This layer modeled the relationships between
different mortals such that they made their decisions as to
where they felt safe (or who they wanted to avoid).
Unfortunately, much of this behaviour was hidden by more direct
behaviour - such as the mortals running screaming from the
haunting, or fainting. However, it is possible to see mortals
going to certain rooms that they feel safe in and a few other
behaviours originating in the affinity layer.
Our previous Star Wars example can be used to demonstrate an
affinity system in action. In this case we have an affinity
value from Han to Luke that starts at neutral (0) and goes up or
down certain amounts in response to the player's activities. For
example:
Initial State:
Affinity (Han, Luke) = 0
Luke and Han bond:
+ 5 Affinity (Han, Luke)
Each time Luke rescues Han:
+ 10 Affinity (Han, Luke)
Each time Luke accidentally hits Han in the foot with his
light sabre:
-3 Affinity (Han, Luke)
A possible condition to test whether or not Han acts the hero in
the finale might be:
If Affinity (Han, Luke) > 5 Then
Saves Luke
Under this system, if Luke and Han bond, Luke can get away with
hitting him in the foot once, but if he's reduced to eight toes,
Luke is toast in the trench. And rescuing Han would cover Luke
from another three accidents or so. Of course this
representation is farcical, but it represents the basic
principles behind an affinity system.
However, now we are using an affinity system, we do not have to
focus on a single outcome. If an affinity of +5 is enough to get
him to take a small risk by popping into the battle for about
five seconds, a larger affinity might persuade him to play the
real hero and get in the battle from the start:
If Affinity (Han, Luke) > 20 Then
Fights in Death Star Battle
Else If Affinity (Han, Luke) > 5 Then
Saves Luke
And let's face it: there has to be limit to the number of digits
Han will allow Luke to accidentally sever:
If Affinity (Han, Luke) > 20 Then
Fights in Death Star Battle
Else If Affinity (Han, Luke) > 5 Then
Saves Luke
Else If Affinity (Han, Luke) < -30 Then
Shoots Luke Dead
Under this condition, if Luke manages to slice off ten or more
of Han's digits, Han will shoot Luke dead on the spot (assuming
he hasn't just lost both hands). If Luke had rescued him a
couple of times, the number of amputations might have to be
higher - if they bond and Luke rescues Han twice earlier in the
story, Han still has one finger left to pull the trigger on his
blaster and reduce the irritating farm boy to Bantha fodder.
The idea of affinity systems is being developed in FreeSpeak as
a means of providing case-based dialogue, such that the dialogue
for non-player characters varies in accordance to the player's
actions. The approach should allow for a greater feeling of
immersion at very little cost. Additionally, plot branches can
occur on the basis of character affinities within the manageable
framework that the FreeSpeak system provides, a technique which
has not yet been seen in games.
Algorithms
The basis of algorithmic interactive characters is to use a
mathematical model to represent character attitudes and
emotions. A distinction should be made between AI algorithms for
the behaviour of characters, and algorithms for representing
their personality and attitudes. The former is ubiquitous in
current games, but the behaviour is usually based entirely
around goal-oriented activities (find the player, defeat the
player in battle). What we are concerned about in this section
is means of reflecting the emotional world of characters
mathematically.
The simplest algorithmic representation may be a probabilistic
approach. Concluding our comparisons in the Star Wars milieu,
consider this formula:
P(Save) = Rescues
_______________
Rescues + Wounds
In this formula, the probability that Han will save Luke at the
end of the story is equal to the number of times Luke rescues
Han divided by the number of rescues plus the number of light
sabre wounds. So if Luke never rescues Han, the probability is 0
(it won't happen). If he rescues Han and never injures him, the
probability is 1 (it will definitely happen). If there are two
rescues, but one wound, the probability is 0.666 (66% chance);
if there is one rescue and nine wounds, the probability is 0.1
(10% chance). Again, this is vastly simplistic, but it
demonstrates the basic principle.
The trouble with probabilistic behaviour in games is that if it
only happens once or twice, it seems to be essentially random.
For example, in the last example, a fingerless Han might still
come to rescue Luke because there is still a random chance - but
the player has no appreciation of the hidden random system that
gave that result. For this reason, probabilistic behaviour is
best used when it is going to be spread across a large number of
events or entities, where the probabilities can be seen by the
player as proportions of a reacting group. This also makes it
largely unsuitable for the behaviour of individuals.
There are more complex approaches, such as International Hobo's
PsiScape, which models the emotional relationships between
characters using a field model (as if the emotional connections
were like a magnetic or gravitational field). Under this system,
one looks for attractive and repulsive forces and overlays the
different fields in order to determine behaviour - individuals
therefore move like iron filings in an ever-changing magnetic
field.
A basic tech demo for PsiScape mapped the behaviour of warriors
on a battlefield using a field which represent the balance
between an individual's fear and duty. Anything that an
individual would find intimidating was a repulsive force,
anything that an individual would feel safe near was an
attractive force, whilst an attractive force representing their
sense of duty pulled them towards the enemy. The scale at which
an individual was affected by these forces was specified by a
number of variables which represented the personality of that
individual. The numbers varied as a result of actions in the
battle - so a hero that slew a powerful foe would suddenly be a
source of fear for the allies of the slain leader.
The result was a system in which the warriors moved in battle
based on their emotional state. Cowards grouped with their
allies, and avoided tough enemies, whilst heroic characters
dived into the fray and - provided they were able to live long
enough - eventually terrified the enemy enough to force them to
withdraw. The effects of landscape could be added by a static
vector field that would be superimposed (although complex
battlefields require some additional mechanics to become
tenable).
In principle, dialogue could be generated by considering the
strongest forces acting on an individual: if their direction of
movement was governed by fear of a strong foe, their dialogue
could reflect their cowardly attitude (or reference the person
they were running from), whilst a character who was trapped
between two strong forces - fear pushing away, but duty just
pulling them forward - could make dashing gung ho comments as
they bury themselves in the fray.
The PsiScape principle could be applied to interactive
characters at a different scale. Imagine a world in which
different characters could be affected by a number of different
fields. Greed, fear, loyalty, fraternity, love; territoriality;
all could be represented by a PsiScape field, and each character
would respond to some of the fields. Their movements in the
world could be governed by the balance of fields, just as the
position on the battlefield was determined in the PsiScape tech
demo. Imagine a merchant motivated by greed and fear alone. If
you encounter them in a road, she can comment that she is
heading to the town ahead because of they've struck gold (which
would place a source of greed in the town, which would be the
strongest force acting on the merchant). Similarly, a refugee
might be found in a shanty town because invaders have taken over
his village. Since fear of the invaders was the force that
overpowered the strong territorial force to stay in the village,
he might comment about his hatred for the invading force.
This field-driven approach to interactive characters has
considerable potential, but is not yet at a state whereby we can
expect it to appear in computer games any time soon.
Nonetheless, it shows the extent to which algorithmic character
behaviour might impact on interactive storytelling in the
future. It is likely that lessons learnt in interactive plots
and affinity-based dialogue systems will strongly influence the
future of algorithmic characters.
#Post#: 68--------------------------------------------------
Re: Foundations of Interactive Storytelling
DIR By: Pam
Date: May 31, 2021, 1:08 pm
---------------------------------------------------------
Making Interactive Stories Manageable
In order to safely undertake interactive stories, the game
designer (or story designer) must take into account the needs of
everyone in the development team with respect to the story
design. There are specific vulnerabilities introduced by
choosing to go beyond a linear plot and cardboard characters,
and the team must be prepared for the problems and pitfalls, as
well as steps needed to maximise the benefits of introducing an
interactive story.
The production process needs to take into account several shifts
in the usual needs of a project:
More Pre-production
It is important that the plot skeletons for the story are set
down on paper before the programmers and artists break ground on
anything other than research or prototyping. Similarly, if
interactive characters are to be used, the parametric design
should be paper-tested or prototyped before the main game is
constructed.
This adds to the pre-production phase, although it need not add
much cost of development as only the design (and dialogue
scripting) team is needed for this pre-production.
Early Script Delivery
The usual system for script delivery is to only write the story
materials after the game is already 50-90% complete). This is
bad practice for most games, since the story is best developed
in parallel with the design, but it is not acceptable for
interactive stories. The dialogue script should be delivered as
soon as is humanly possible.
QA Should Start Earlier
Ideally, the plot skeleton should be implementable so that the
Quality Assurance team can begin testing it as soon as possible.
If the plot skeleton exists only on paper until most of the game
has been implemented, there may be insufficient time to debug
the plot. This will add to the cost of development slightly, but
only a small QA team is needed to test a plot skeleton.
Tweaking Time Desirable
If there are any parametric elements to the interactive story
(especially if there are algorithmic characters) the team should
have an opportunity to adjust parametrics in the latter stages
of development. Every project would like to have this 'tweaking
time', but it is more or less essential for interactive stories.
Because of the extra costs accrued in pre-production, QA and in
tweaking time, interactive stories will for the time being be
constrained to big-budget projects (which can afford extra
expense) and 'art house games' (those with production values far
below the mass market expectations). For most projects, which
are on a tight budget for both time and money, any introduction
of interactive story elements must be handled with great care.
Once the decision to include these elements, however, certain
steps will minimise some of the typical problems:
Ensure multiple people know plot skeleton
It is vital that more than one person in the development team is
familiar with the plot skeleton of the story. Not only will this
improve the team's overall flexibility within the framework of
the story, but it will limit the risk of severe delays in the
event of loss of key personnel (if only one person knows the
plot skeleton and they quit, the game will be in big trouble!)
Make sure all uses of locations known
The game designer (or story designer) must ensure that the
producer (or game designer) provides a summary of all the times
a location is used, and for what reason. Interactive stories are
likely to reuse locations, and the artists and programmers must
know everything that a location will be used for if they are to
do their jobs to the best of their abilities.
In addition to avoiding the pitfalls, certain steps will aid in
maximising the benefits of an interactive story:
Record and report all incidentally generated sub-locations
When artists work at implementing what is required for a
location, they usually create some 'sub-locations' from their
own artistic sensibilities in order to make the location look
right. These extra locations are effectively 'free', and it may
be worth taking advantage of them. It might be possible to use
these instead of a different location, or to create a new scene.
Record dialogue as late as possible
To provide maximum freedom for minor plot restructuring and
additional scenes, translate and record dialogue at a late point
in the project. A good rule of thumb for all computer games
scripts is 'write early, record late'. Try to get the script
written as soon as the main details have been locked down, but
hold off recording with voice actors (and translating to other
languages) until the latest, safe point in the development
cycle.
Finally, it is worth looking at a few issues that affect
marketing:
Hype new technology
Take advantage of any non-linearity or interactive narrative
elements as PR opportunities. Few games have them, so make sure
that marketing know that this game has genuine unique selling
points (USPs), rather than fairly familiar selling points.
Educate the Audience
It is important to ensure that the appropriate target
demographics are aware of their freedom to choose in the game.
As above, this will act as a selling point, but also it will
improve word of mouth promotion after game is released which can
make a big difference in the long term sales potential of the
game, and of any brand that it creates.
With a little forethought and care, interactive stories can be
integrated into a game project with minimal overall cost or
risk, but as ever the games designer must pay attention to the
many different participants in the game development process if
they are going to do their job to the best of their ability.
#Post#: 69--------------------------------------------------
Re: Foundations of Interactive Storytelling
DIR By: Pam
Date: May 31, 2021, 1:09 pm
---------------------------------------------------------
Conclusion
We have seen how the field of interactive storytelling has grown
out of the table top role-playing games of the 1970's and
onwards, and discussed two ways in which interactive
storytelling is likely to become more widespread over the next
few decades.
Interactive plots offer the potential for genuinely non-linear
narratives, although care must be taken that the design work
that goes into creating the interactive plot is felt by the
player. It is easy to put in details that only the games
designer will appreciate, and this is especially true if an
interactive plot is used in a long game: few players will replay
it, so the interactive elements will be largely invisible
(although the player may enjoy the game more because more of
their wishes and desires are covered by the game as allowable
courses of action).
Dynamic object oriented narratives may provide a means to
explore interactive plots in a robust and cost-effective manner.
If they deliver all that is hoped, players will experience a new
breed of games in which their choices are reflected in the
development of the story without the game requiring a lot of
'unseen' material being developed.
Interactive characters are still at a simplistic stage, but
affinity systems promise interesting dialogue design
possibilities in the near future, and field-based approaches (or
other procedural algorithms) may in themselves present new ways
of structuring game stories. It may be possible to create a
dynamic world in which stories create themselves from the
interactive materials.
The first games to successfully implement and market high-order
interactive storytelling will almost certainly found new genres
and acquire brand dominance of that genre - this is the mass
market prize for interactive storytelling. For the time being,
however, we are likely to see interactive stories emerging from
the fringes of the games industry in niche products and 'art
house games'.
Given the attachment to stories that humans display, and the
sense of satisfaction engendered by a feeling of involvement in
a story as it develops, it seems likely that interactive
storytelling will become an increasingly important aspect of
narrative game design over the next two decades. The time may
come when even the mass market appreciates the advantage of
giving players the ability to make meaningful choices within a
game world.
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