<s>
A	O
dialogue	B-Application
tree	I-Application
,	O
or	O
conversation	B-Application
tree	I-Application
,	O
is	O
a	O
gameplay	O
mechanic	O
that	O
is	O
used	O
throughout	O
many	O
adventure	O
games	O
(	O
including	O
action-adventure	O
games	O
)	O
and	O
role-playing	O
video	O
games	O
.	O
</s>
<s>
The	O
concept	O
of	O
the	O
dialogue	B-Application
tree	I-Application
has	O
existed	O
long	O
before	O
the	O
advent	O
of	O
video	O
games	O
.	O
</s>
<s>
The	O
earliest	O
known	O
dialogue	B-Application
tree	I-Application
is	O
described	O
in	O
"	O
The	O
Garden	O
of	O
Forking	O
Paths	O
"	O
,	O
a	O
1941	O
short	O
story	O
by	O
Jorge	O
Luis	O
Borges	O
,	O
in	O
which	O
the	O
combination	O
book	O
of	O
Ts'ui	O
Pên	O
allows	O
all	O
major	O
outcomes	O
from	O
an	O
event	O
branch	O
into	O
their	O
own	O
chapters	O
.	O
</s>
<s>
The	O
first	O
computer	O
dialogue	B-General_Concept
system	I-General_Concept
was	O
featured	O
in	O
ELIZA	B-Application
,	O
a	O
primitive	O
natural	B-Language
language	I-Language
processing	I-Language
computer	B-Application
program	I-Application
written	O
by	O
Joseph	O
Weizenbaum	O
between	O
1964	O
and	O
1966	O
.	O
</s>
<s>
The	O
program	O
emulated	O
interaction	O
between	O
the	O
user	O
and	O
an	O
artificial	B-Application
therapist	O
.	O
</s>
<s>
These	O
conversations	O
are	O
said	O
to	O
be	O
designed	O
as	O
a	O
tree	B-Data_Structure
structure	I-Data_Structure
,	O
with	O
players	O
deciding	O
between	O
each	O
branch	O
of	O
dialog	O
to	O
pursue	O
.	O
</s>
<s>
Unlike	O
a	O
branching	O
story	O
,	O
players	O
may	O
return	O
to	O
earlier	O
parts	O
of	O
a	O
conversation	B-Application
tree	I-Application
and	O
repeat	O
them	O
.	O
</s>
<s>
However	O
,	O
these	O
are	O
usually	O
not	O
real	O
tree	B-Application
data	I-Application
structure	I-Application
in	O
programmers	O
sense	O
,	O
because	O
they	O
contain	O
cycles	O
as	O
can	O
be	O
seen	O
on	O
illustration	O
on	O
this	O
page	O
.	O
</s>
<s>
Certain	O
game	O
genres	O
revolve	O
almost	O
entirely	O
around	O
character	O
interactions	O
,	O
including	O
visual	O
novels	O
such	O
as	O
Ace	B-Application
Attorney	I-Application
and	O
dating	O
sims	O
such	O
as	O
Tokimeki	B-Application
Memorial	I-Application
,	O
usually	O
featuring	O
complex	O
branching	O
dialogues	O
and	O
often	O
presenting	O
the	O
player	O
's	O
possible	O
responses	O
word-for-word	O
as	O
the	O
player	O
character	O
would	O
say	O
them	O
.	O
</s>
<s>
Games	O
revolving	O
around	O
relationship-building	O
,	O
including	O
visual	O
novels	O
,	O
dating	O
sims	O
such	O
as	O
Tokimeki	B-Application
Memorial	I-Application
,	O
and	O
some	O
role-playing	O
games	O
such	O
as	O
Shin	B-Application
Megami	I-Application
Tensei	I-Application
:	I-Application
Persona	I-Application
,	O
often	O
give	O
choices	O
that	O
have	O
a	O
different	O
number	O
of	O
associated	O
"	O
mood	O
points	O
"	O
which	O
influence	O
a	O
player	O
character	O
's	O
relationship	O
and	O
future	O
conversations	O
with	O
a	O
non-player	O
character	O
.	O
</s>
<s>
These	O
games	O
often	O
feature	O
a	O
day-night	B-Protocol
cycle	I-Protocol
with	O
a	O
time	O
scheduling	O
system	O
that	O
provides	O
context	O
and	O
relevance	O
to	O
character	O
interactions	O
,	O
allowing	O
players	O
to	O
choose	O
when	O
and	O
if	O
to	O
interact	O
with	O
certain	O
characters	O
,	O
which	O
in	O
turn	O
influences	O
their	O
responses	O
during	O
later	O
conversations	O
.	O
</s>
<s>
Some	O
games	O
use	O
a	O
real-time	O
conversation	O
system	O
,	O
giving	O
the	O
player	O
only	O
a	O
few	O
seconds	O
to	O
respond	O
to	O
a	O
non-player	O
character	O
,	O
such	O
as	O
Sega	O
's	O
Sakura	B-Application
Wars	I-Application
and	O
Alpha	B-Application
Protocol	I-Application
.	O
</s>
<s>
Another	O
variation	O
of	O
branching	O
dialogues	O
can	O
be	O
seen	O
in	O
the	O
adventure	O
game	O
Culpa	B-Application
Innata	I-Application
,	O
where	O
the	O
player	O
chooses	O
a	O
tactic	O
at	O
the	O
beginning	O
of	O
a	O
conversation	O
,	O
such	O
as	O
using	O
either	O
a	O
formal	O
,	O
casual	O
or	O
accusatory	O
manner	O
,	O
that	O
affects	O
the	O
tone	O
of	O
the	O
conversation	O
and	O
the	O
information	O
gleaned	O
from	O
the	O
interviewee	O
.	O
</s>
<s>
This	O
mechanism	O
allows	O
game	O
designers	O
to	O
provide	O
interactive	O
conversations	O
with	O
nonplayer	O
characters	O
without	O
having	O
to	O
tackle	O
the	O
challenges	O
of	O
natural	B-Language
language	I-Language
processing	I-Language
in	O
the	O
field	O
of	O
artificial	B-Application
intelligence	I-Application
.	I-Application
</s>
<s>
In	O
games	O
such	O
as	O
Monkey	B-Application
Island	I-Application
,	O
these	O
conversations	O
can	O
help	O
demonstrate	O
the	O
personality	O
of	O
certain	O
characters	O
.	O
</s>
