<s>
In	O
video	O
games	O
,	O
artificial	B-Application
intelligence	I-Application
(	O
AI	B-Application
)	O
is	O
used	O
to	O
generate	O
responsive	O
,	O
adaptive	O
or	O
intelligent	O
behaviors	O
primarily	O
in	O
non-player	O
characters	O
(	O
NPCs	O
)	O
similar	O
to	O
human-like	O
intelligence	O
.	O
</s>
<s>
Artificial	B-Application
intelligence	I-Application
has	O
been	O
an	O
integral	O
part	O
of	O
video	O
games	O
since	O
their	O
inception	O
in	O
the	O
1950s	O
.	O
</s>
<s>
AI	B-Application
in	I-Application
video	I-Application
games	I-Application
is	O
a	O
distinct	O
subfield	O
and	O
differs	O
from	O
academic	O
AI	B-Application
.	O
</s>
<s>
During	O
the	O
golden	O
age	O
of	O
arcade	O
video	O
games	O
the	O
idea	O
of	O
AI	B-Application
opponents	O
was	O
largely	O
popularized	O
in	O
the	O
form	O
of	O
graduated	O
difficulty	O
levels	O
,	O
distinct	O
movement	O
patterns	O
,	O
and	O
in-game	O
events	O
dependent	O
on	O
the	O
player	O
's	O
input	O
.	O
</s>
<s>
Modern	O
games	O
often	O
implement	O
existing	O
techniques	O
such	O
as	O
pathfinding	B-Algorithm
and	O
decision	B-Algorithm
trees	I-Algorithm
to	O
guide	O
the	O
actions	O
of	O
NPCs	O
.	O
</s>
<s>
AI	B-Application
is	O
often	O
used	O
in	O
mechanisms	O
which	O
are	O
not	O
immediately	O
visible	O
to	O
the	O
user	O
,	O
such	O
as	O
data	B-Application
mining	I-Application
and	O
procedural-content	O
generation	O
.	O
</s>
<s>
In	O
general	O
,	O
game	B-Application
AI	I-Application
does	O
not	O
,	O
as	O
might	O
be	O
thought	O
and	O
sometimes	O
is	O
depicted	O
to	O
be	O
the	O
case	O
,	O
mean	O
a	O
realization	O
of	O
an	O
artificial	O
person	O
corresponding	O
to	O
an	O
NPC	O
in	O
the	O
manner	O
of	O
the	O
Turing	O
test	O
or	O
an	O
artificial	O
general	O
intelligence	O
.	O
</s>
<s>
The	O
term	O
"	O
game	B-Application
AI	I-Application
"	O
is	O
used	O
to	O
refer	O
to	O
a	O
broad	O
set	O
of	O
algorithms	O
that	O
also	O
include	O
techniques	O
from	O
control	O
theory	O
,	O
robotics	O
,	O
computer	O
graphics	O
and	O
computer	B-General_Concept
science	I-General_Concept
in	O
general	O
,	O
and	O
so	O
video	B-Application
game	I-Application
AI	I-Application
may	O
often	O
not	O
constitute	O
"	O
true	O
AI	B-Application
"	O
in	O
that	O
such	O
techniques	O
do	O
not	O
necessarily	O
facilitate	O
computer	O
learning	O
or	O
other	O
standard	O
criteria	O
,	O
only	O
constituting	O
"	O
automated	O
computation	O
"	O
or	O
a	O
predetermined	O
and	O
limited	O
set	O
of	O
responses	O
to	O
a	O
predetermined	O
and	O
limited	O
set	O
of	O
inputs	O
.	O
</s>
<s>
Many	O
industries	O
and	O
corporate	O
voices	O
claim	O
that	O
so-called	O
video	B-Application
game	I-Application
AI	I-Application
has	O
come	O
a	O
long	O
way	O
in	O
the	O
sense	O
that	O
it	O
has	O
revolutionized	O
the	O
way	O
humans	O
interact	O
with	O
all	O
forms	O
of	O
technology	O
,	O
although	O
many	O
expert	O
researchers	O
are	O
skeptical	O
of	O
such	O
claims	O
,	O
and	O
particularly	O
of	O
the	O
notion	O
that	O
such	O
technologies	O
fit	O
the	O
definition	O
of	O
"	O
intelligence	O
"	O
standardly	O
used	O
in	O
the	O
cognitive	O
sciences	O
.	O
</s>
<s>
Industry	O
voices	O
make	O
the	O
argument	O
that	O
AI	B-Application
has	O
become	O
more	O
versatile	O
in	O
the	O
way	O
we	O
use	O
all	O
technological	O
devices	O
for	O
more	O
than	O
their	O
intended	O
purpose	O
because	O
the	O
AI	B-Application
allows	O
the	O
technology	O
to	O
operate	O
in	O
multiple	O
ways	O
,	O
allegedly	O
developing	O
their	O
own	O
personalities	O
and	O
carrying	O
out	O
complex	O
instructions	O
of	O
the	O
user	O
.	O
</s>
<s>
However	O
,	O
people	O
in	O
the	O
field	O
of	O
AI	B-Application
have	O
argued	O
that	O
video	B-Application
game	I-Application
AI	I-Application
is	O
not	O
true	O
intelligence	O
,	O
but	O
an	O
advertising	O
buzzword	O
used	O
to	O
describe	O
computer	O
programs	O
that	O
use	O
simple	O
sorting	O
and	O
matching	O
algorithms	O
to	O
create	O
the	O
illusion	O
of	O
intelligent	O
behavior	O
while	O
bestowing	O
software	O
with	O
a	O
misleading	O
aura	O
of	O
scientific	O
or	O
technological	O
complexity	O
and	O
advancement	O
.	O
</s>
<s>
Since	O
game	B-Application
AI	I-Application
for	O
NPCs	O
is	O
centered	O
on	O
appearance	O
of	O
intelligence	O
and	O
good	O
gameplay	O
within	O
environment	O
restrictions	O
,	O
its	O
approach	O
is	O
very	O
different	O
from	O
that	O
of	O
traditional	O
AI	B-Application
.	O
</s>
<s>
Game	O
playing	O
was	O
an	O
area	O
of	O
research	O
in	O
AI	B-Application
from	O
its	O
inception	O
.	O
</s>
<s>
One	O
of	O
the	O
first	O
examples	O
of	O
AI	B-Application
is	O
the	O
computerized	O
game	O
of	O
Nim	B-Application
made	O
in	O
1951	O
and	O
published	O
in	O
1952	O
.	O
</s>
<s>
Despite	O
being	O
advanced	O
technology	O
in	O
the	O
year	O
it	O
was	O
made	O
,	O
20	O
years	O
before	O
Pong	B-Application
,	O
the	O
game	O
took	O
the	O
form	O
of	O
a	O
relatively	O
small	O
box	O
and	O
was	O
able	O
to	O
regularly	O
win	O
games	O
even	O
against	O
highly	O
skilled	O
players	O
of	O
the	O
game	O
.	O
</s>
<s>
In	O
1951	O
,	O
using	O
the	O
Ferranti	B-Device
Mark	I-Device
1	I-Device
machine	O
of	O
the	O
University	O
of	O
Manchester	O
,	O
Christopher	O
Strachey	O
wrote	O
a	O
checkers	O
program	O
and	O
Dietrich	O
Prinz	O
wrote	O
one	O
for	O
chess	B-Application
.	O
</s>
<s>
Work	O
on	O
checkers	O
and	O
chess	B-Application
would	O
culminate	O
in	O
the	O
defeat	O
of	O
Garry	O
Kasparov	O
by	O
IBM	O
's	O
Deep	B-General_Concept
Blue	I-General_Concept
computer	O
in	O
1997	O
.	O
</s>
<s>
The	O
first	O
video	O
games	O
developed	O
in	O
the	O
1960s	O
and	O
early	O
1970s	O
,	O
like	O
Spacewar	O
!,	O
Pong	B-Application
,	O
and	O
Gotcha	B-Application
(	O
1973	O
)	O
,	O
were	O
games	O
implemented	O
on	O
discrete	O
logic	O
and	O
strictly	O
based	O
on	O
the	O
competition	O
of	O
two	O
players	O
,	O
without	O
AI	B-Application
.	O
</s>
<s>
The	O
first	O
notable	O
ones	O
for	O
the	O
arcade	O
appeared	O
in	O
1974	O
:	O
the	O
Taito	O
game	O
Speed	B-Application
Race	I-Application
(	O
racing	O
video	O
game	O
)	O
and	O
the	O
Atari	O
games	O
Qwak	B-Application
(	O
duck	O
hunting	O
light	O
gun	O
shooter	O
)	O
and	O
Pursuit	B-Application
(	O
fighter	O
aircraft	O
dogfighting	O
simulator	O
)	O
.	O
</s>
<s>
Two	O
text-based	O
computer	O
games	O
from	O
1972	O
,	O
Hunt	B-Application
the	I-Application
Wumpus	I-Application
and	O
Star	O
Trek	O
,	O
also	O
had	O
enemies	O
.	O
</s>
<s>
The	O
incorporation	O
of	O
microprocessors	B-Architecture
would	O
allow	O
more	O
computation	O
and	O
random	O
elements	O
overlaid	O
into	O
movement	O
patterns	O
.	O
</s>
<s>
It	O
was	O
during	O
the	O
golden	O
age	O
of	O
video	O
arcade	O
games	O
that	O
the	O
idea	O
of	O
AI	B-Application
opponents	O
was	O
largely	O
popularized	O
,	O
due	O
to	O
the	O
success	O
of	O
Space	B-Application
Invaders	I-Application
(	O
1978	O
)	O
,	O
which	O
sported	O
an	O
increasing	O
difficulty	O
level	O
,	O
distinct	O
movement	O
patterns	O
,	O
and	O
in-game	O
events	O
dependent	O
on	O
hash	B-Error_Name
functions	I-Error_Name
based	O
on	O
the	O
player	O
's	O
input	O
.	O
</s>
<s>
Galaxian	B-Application
(	O
1979	O
)	O
added	O
more	O
complex	O
and	O
varied	O
enemy	O
movements	O
,	O
including	O
maneuvers	O
by	O
individual	O
enemies	O
who	O
break	O
out	O
of	O
formation	O
.	O
</s>
<s>
Pac-Man	B-Application
(	O
1980	O
)	O
introduced	O
AI	B-Application
patterns	O
to	O
maze	B-Application
games	I-Application
,	O
with	O
the	O
added	O
quirk	O
of	O
different	O
personalities	O
for	O
each	O
enemy	O
.	O
</s>
<s>
Karate	B-Device
Champ	I-Device
(	O
1984	O
)	O
later	O
introduced	O
AI	B-Application
patterns	O
to	O
fighting	O
games	O
.	O
</s>
<s>
First	O
Queen	O
(	O
1988	O
)	O
was	O
a	O
tactical	O
action	B-Application
RPG	I-Application
which	O
featured	O
characters	O
that	O
can	O
be	O
controlled	O
by	O
the	O
computer	O
's	O
AI	B-Application
in	O
following	O
the	O
leader	O
.	O
</s>
<s>
The	O
role-playing	O
video	O
game	O
Dragon	B-Application
Quest	I-Application
IV	I-Application
(	O
1990	O
)	O
introduced	O
a	O
"	O
Tactics	O
"	O
system	O
,	O
where	O
the	O
user	O
can	O
adjust	O
the	O
AI	B-Application
routines	O
of	O
non-player	O
characters	O
during	O
battle	O
,	O
a	O
concept	O
later	O
introduced	O
to	O
the	O
action	B-Application
role-playing	I-Application
game	I-Application
genre	O
by	O
Secret	B-Application
of	I-Application
Mana	I-Application
(	O
1993	O
)	O
.	O
</s>
<s>
Games	O
like	O
Madden	O
Football	O
,	O
Earl	B-Application
Weaver	I-Application
Baseball	I-Application
and	O
Tony	B-Application
La	I-Application
Russa	I-Application
Baseball	I-Application
all	O
based	O
their	O
AI	B-Application
in	O
an	O
attempt	O
to	O
duplicate	O
on	O
the	O
computer	O
the	O
coaching	O
or	O
managerial	O
style	O
of	O
the	O
selected	O
celebrity	O
.	O
</s>
<s>
Later	O
sports	O
titles	O
allowed	O
users	O
to	O
"	O
tune	O
"	O
variables	O
in	O
the	O
AI	B-Application
to	O
produce	O
a	O
player-defined	O
managerial	O
or	O
coaching	O
strategy	O
.	O
</s>
<s>
The	O
emergence	O
of	O
new	O
game	O
genres	O
in	O
the	O
1990s	O
prompted	O
the	O
use	O
of	O
formal	O
AI	B-Application
tools	O
like	O
finite	B-Architecture
state	I-Architecture
machines	I-Architecture
.	O
</s>
<s>
Real-time	O
strategy	O
games	O
taxed	O
the	O
AI	B-Application
with	O
many	O
objects	O
,	O
incomplete	O
information	O
,	O
pathfinding	B-Algorithm
problems	O
,	O
real-time	O
decisions	O
and	O
economic	O
planning	O
,	O
among	O
other	O
things	O
.	O
</s>
<s>
Herzog	B-Application
Zwei	I-Application
(	O
1989	O
)	O
,	O
for	O
example	O
,	O
had	O
almost	O
broken	O
pathfinding	B-Algorithm
and	O
very	O
basic	O
three-state	O
state	B-Architecture
machines	I-Architecture
for	O
unit	O
control	O
,	O
and	O
Dune	B-Application
II	I-Application
(	O
1992	O
)	O
attacked	O
the	O
players	O
 '	O
base	O
in	O
a	O
beeline	O
and	O
used	O
numerous	O
cheats	O
.	O
</s>
<s>
Later	O
games	O
in	O
the	O
genre	O
exhibited	O
more	O
sophisticated	O
AI	B-Application
.	O
</s>
<s>
Later	O
games	O
have	O
used	O
bottom-up	O
AI	B-Application
methods	O
,	O
such	O
as	O
the	O
emergent	O
behaviour	O
and	O
evaluation	O
of	O
player	O
actions	O
in	O
games	O
like	O
Creatures	B-Application
or	O
Black	B-Application
&	I-Application
White	I-Application
.	O
</s>
<s>
Façade	B-Application
(	O
interactive	O
story	O
)	O
was	O
released	O
in	O
2005	O
and	O
used	O
interactive	O
multiple	O
way	O
dialogs	O
and	O
AI	B-Application
as	O
the	O
main	O
aspect	O
of	O
game	O
.	O
</s>
<s>
Games	O
have	O
provided	O
an	O
environment	O
for	O
developing	O
artificial	B-Application
intelligence	I-Application
with	O
potential	O
applications	O
beyond	O
gameplay	O
.	O
</s>
<s>
Examples	O
include	O
Watson	B-Application
,	O
a	O
Jeopardy	O
!	O
-playing	O
computer	O
;	O
and	O
the	O
RoboCup	O
tournament	O
,	O
where	O
robots	O
are	O
trained	O
to	O
compete	O
in	O
soccer	O
.	O
</s>
<s>
Many	O
experts	O
complain	O
that	O
the	O
"	O
AI	B-Application
"	O
in	O
the	O
term	O
"	O
game	B-Application
AI	I-Application
"	O
overstates	O
its	O
worth	O
,	O
as	O
game	B-Application
AI	I-Application
is	O
not	O
about	O
intelligence	O
,	O
and	O
shares	O
few	O
of	O
the	O
objectives	O
of	O
the	O
academic	O
field	O
of	O
AI	B-Application
.	O
</s>
<s>
Whereas	O
"	O
real	O
AI	B-Application
"	O
addresses	O
fields	O
of	O
machine	O
learning	O
,	O
decision	O
making	O
based	O
on	O
arbitrary	O
data	O
input	O
,	O
and	O
even	O
the	O
ultimate	O
goal	O
of	O
strong	O
AI	B-Application
that	O
can	O
reason	O
,	O
"	O
game	B-Application
AI	I-Application
"	O
often	O
consists	O
of	O
a	O
half-dozen	O
rules	O
of	O
thumb	O
,	O
or	O
heuristics	B-Algorithm
,	O
that	O
are	O
just	O
enough	O
to	O
give	O
a	O
good	O
gameplay	O
experience	O
.	O
</s>
<s>
Historically	O
,	O
academic	O
game-AI	O
projects	O
have	O
been	O
relatively	O
separate	O
from	O
commercial	O
products	O
because	O
the	O
academic	O
approaches	O
tended	O
to	O
be	O
simple	O
and	O
non-scalable	O
.	O
</s>
<s>
Commercial	O
game	B-Application
AI	I-Application
has	O
developed	O
its	O
own	O
set	O
of	O
tools	O
,	O
which	O
have	O
been	O
sufficient	O
to	O
give	O
good	O
performance	O
in	O
many	O
cases	O
.	O
</s>
<s>
Game	O
developers	O
 '	O
increasing	O
awareness	O
of	O
academic	O
AI	B-Application
and	O
a	O
growing	O
interest	O
in	O
computer	O
games	O
by	O
the	O
academic	O
community	O
is	O
causing	O
the	O
definition	O
of	O
what	O
counts	O
as	O
AI	B-Application
in	O
a	O
game	O
to	O
become	O
less	O
idiosyncratic	O
.	O
</s>
<s>
Nevertheless	O
,	O
significant	O
differences	O
between	O
different	O
application	O
domains	O
of	O
AI	B-Application
mean	O
that	O
game	B-Application
AI	I-Application
can	O
still	O
be	O
viewed	O
as	O
a	O
distinct	O
subfield	O
of	O
AI	B-Application
.	O
</s>
<s>
In	O
particular	O
,	O
the	O
ability	O
to	O
legitimately	O
solve	O
some	O
AI	B-Application
problems	O
in	O
games	O
by	O
cheating	O
creates	O
an	O
important	O
distinction	O
.	O
</s>
<s>
For	O
example	O
,	O
inferring	O
the	O
position	O
of	O
an	O
unseen	O
object	O
from	O
past	O
observations	O
can	O
be	O
a	O
difficult	O
problem	O
when	O
AI	B-Application
is	O
applied	O
to	O
robotics	O
,	O
but	O
in	O
a	O
computer	O
game	O
a	O
NPC	O
can	O
simply	O
look	O
up	O
the	O
position	O
in	O
the	O
game	O
's	O
scene	B-Data_Structure
graph	I-Data_Structure
.	O
</s>
<s>
But	O
its	O
possibility	O
serves	O
to	O
distinguish	O
game	B-Application
AI	I-Application
and	O
leads	O
to	O
new	O
problems	O
to	O
solve	O
,	O
such	O
as	O
when	O
and	O
how	O
to	O
cheat	O
.	O
</s>
<s>
The	O
major	O
limitation	O
to	O
strong	O
AI	B-Application
is	O
the	O
inherent	O
depth	O
of	O
thinking	O
and	O
the	O
extreme	O
complexity	O
of	O
the	O
decision-making	O
process	O
.	O
</s>
<s>
This	O
means	O
that	O
although	O
it	O
would	O
be	O
then	O
theoretically	O
possible	O
to	O
make	O
"	O
smart	O
"	O
AI	B-Application
the	O
problem	O
would	O
take	O
considerable	O
processing	O
power	O
.	O
</s>
<s>
The	O
most	O
obvious	O
is	O
in	O
the	O
control	O
of	O
any	O
NPCs	O
in	O
the	O
game	O
,	O
although	O
"	O
scripting	O
"	O
(	O
decision	B-Algorithm
tree	I-Algorithm
)	O
is	O
currently	O
the	O
most	O
common	O
means	O
of	O
control	O
.	O
</s>
<s>
These	O
handwritten	O
decision	B-Algorithm
trees	I-Algorithm
often	O
result	O
in	O
"	O
artificial	O
stupidity	O
"	O
such	O
as	O
repetitive	O
behavior	O
,	O
loss	O
of	O
immersion	O
,	O
or	O
abnormal	O
behavior	O
in	O
situations	O
the	O
developers	O
did	O
not	O
plan	O
for	O
.	O
</s>
<s>
Pathfinding	B-Algorithm
,	O
another	O
common	O
use	O
for	O
AI	B-Application
,	O
is	O
widely	O
seen	O
in	O
real-time	O
strategy	O
games	O
.	O
</s>
<s>
Pathfinding	B-Algorithm
is	O
the	O
method	O
for	O
determining	O
how	O
to	O
get	O
a	O
NPC	O
from	O
one	O
point	O
on	O
a	O
map	O
to	O
another	O
,	O
taking	O
into	O
consideration	O
the	O
terrain	O
,	O
obstacles	O
and	O
possibly	O
"	O
fog	O
of	O
war	O
"	O
.	O
</s>
<s>
Commercial	O
videogames	O
often	O
use	O
fast	O
and	O
simple	O
"	O
grid-based	O
pathfinding	B-Algorithm
"	O
,	O
wherein	O
the	O
terrain	O
is	O
mapped	O
onto	O
a	O
rigid	O
grid	O
of	O
uniform	O
squares	O
and	O
a	O
pathfinding	B-Algorithm
algorithm	O
such	O
as	O
A*	B-Protocol
or	O
IDA*	B-Protocol
is	O
applied	O
to	O
the	O
grid	O
.	O
</s>
<s>
Instead	O
of	O
just	O
a	O
rigid	O
grid	O
,	O
some	O
games	O
use	O
irregular	O
polygons	O
and	O
assemble	O
a	O
navigation	B-Algorithm
mesh	I-Algorithm
out	O
of	O
the	O
areas	O
of	O
the	O
map	O
that	O
NPCs	O
can	O
walk	O
to	O
.	O
</s>
<s>
In	O
addition	O
,	O
waypoints	O
tend	O
to	O
perform	O
worse	O
than	O
navigation	B-Algorithm
meshes	I-Algorithm
in	O
complex	O
environments	O
.	O
</s>
<s>
Beyond	O
static	O
pathfinding	B-Algorithm
,	O
navigation	O
is	O
a	O
sub-field	O
of	O
Game	B-Application
AI	I-Application
focusing	O
on	O
giving	O
NPCs	O
the	O
capability	O
to	O
navigate	O
in	O
a	O
dynamic	O
environment	O
,	O
finding	O
a	O
path	O
to	O
a	O
target	O
while	O
avoiding	O
collisions	O
with	O
other	O
entities	O
(	O
other	O
NPC	O
,	O
players	O
...	O
)	O
or	O
collaborating	O
with	O
them	O
(	O
group	O
navigation	O
)	O
.	O
</s>
<s>
Navigation	O
in	O
dynamic	O
strategy	O
games	O
with	O
large	O
numbers	O
of	O
units	O
,	O
such	O
as	O
Age	B-Application
of	I-Application
Empires	I-Application
(	O
1997	O
)	O
or	O
Civilization	B-Application
V	I-Application
(	O
2010	O
)	O
,	O
often	O
performs	O
poorly	O
;	O
units	O
often	O
get	O
in	O
the	O
way	O
of	O
other	O
units	O
.	O
</s>
<s>
Rather	O
than	O
improve	O
the	O
Game	B-Application
AI	I-Application
to	O
properly	O
solve	O
a	O
difficult	O
problem	O
in	O
the	O
virtual	O
environment	O
,	O
it	O
is	O
often	O
more	O
cost-effective	O
to	O
just	O
modify	O
the	O
scenario	O
to	O
be	O
more	O
tractable	O
.	O
</s>
<s>
If	O
pathfinding	B-Algorithm
gets	O
bogged	O
down	O
over	O
a	O
specific	O
obstacle	O
,	O
a	O
developer	O
may	O
just	O
end	O
up	O
moving	O
or	O
deleting	O
the	O
obstacle	O
.	O
</s>
<s>
In	O
Half-Life	B-Application
(	O
1998	O
)	O
,	O
the	O
pathfinding	B-Algorithm
algorithm	O
sometimes	O
failed	O
to	O
find	O
a	O
reasonable	O
way	O
for	O
all	O
the	O
NPCs	O
to	O
evade	O
a	O
thrown	O
grenade	O
;	O
rather	O
than	O
allow	O
the	O
NPCs	O
to	O
attempt	O
to	O
bumble	O
out	O
of	O
the	O
way	O
and	O
risk	O
appearing	O
stupid	O
,	O
the	O
developers	O
instead	O
scripted	O
the	O
NPCs	O
to	O
crouch	O
down	O
and	O
cover	O
in	O
place	O
in	O
that	O
situation	O
.	O
</s>
<s>
The	O
AI	B-Application
's	O
ability	O
to	O
be	O
efficient	O
in	O
combat	O
is	O
important	O
in	O
these	O
genres	O
.	O
</s>
<s>
A	O
common	O
goal	O
today	O
is	O
to	O
make	O
the	O
AI	B-Application
more	O
human	O
or	O
at	O
least	O
appear	O
so	O
.	O
</s>
<s>
One	O
of	O
the	O
more	O
positive	O
and	O
efficient	O
features	O
found	O
in	O
modern-day	O
video	B-Application
game	I-Application
AI	I-Application
is	O
the	O
ability	O
to	O
hunt	O
.	O
</s>
<s>
AI	B-Application
originally	O
reacted	O
in	O
a	O
very	O
black	B-Application
and	I-Application
white	I-Application
manner	O
.	O
</s>
<s>
If	O
the	O
player	O
were	O
in	O
a	O
specific	O
area	O
then	O
the	O
AI	B-Application
would	O
react	O
in	O
either	O
a	O
complete	O
offensive	O
manner	O
or	O
be	O
entirely	O
defensive	O
.	O
</s>
<s>
In	O
recent	O
years	O
,	O
the	O
idea	O
of	O
"	O
hunting	O
"	O
has	O
been	O
introduced	O
;	O
in	O
this	O
'	O
hunting	O
 '	O
state	O
the	O
AI	B-Application
will	O
look	O
for	O
realistic	O
markers	O
,	O
such	O
as	O
sounds	O
made	O
by	O
the	O
character	O
or	O
footprints	O
they	O
may	O
have	O
left	O
behind	O
.	O
</s>
<s>
Another	O
development	O
in	O
recent	O
game	B-Application
AI	I-Application
has	O
been	O
the	O
development	O
of	O
"	O
survival	O
instinct	O
"	O
.	O
</s>
<s>
Like	O
a	O
user	O
,	O
the	O
AI	B-Application
can	O
look	O
for	O
cover	O
in	O
a	O
firefight	O
before	O
taking	O
actions	O
that	O
would	O
leave	O
it	O
otherwise	O
vulnerable	O
,	O
such	O
as	O
reloading	O
a	O
weapon	O
or	O
throwing	O
a	O
grenade	O
.	O
</s>
<s>
For	O
example	O
,	O
if	O
the	O
AI	B-Application
is	O
given	O
a	O
command	O
to	O
check	O
its	O
health	O
throughout	O
a	O
game	O
then	O
further	O
commands	O
can	O
be	O
set	O
so	O
that	O
it	O
reacts	O
a	O
specific	O
way	O
at	O
a	O
certain	O
percentage	O
of	O
health	O
.	O
</s>
<s>
If	O
the	O
health	O
is	O
below	O
a	O
certain	O
threshold	O
then	O
the	O
AI	B-Application
can	O
be	O
set	O
to	O
run	O
away	O
from	O
the	O
player	O
and	O
avoid	O
it	O
until	O
another	O
function	O
is	O
triggered	O
.	O
</s>
<s>
Another	O
example	O
could	O
be	O
if	O
the	O
AI	B-Application
notices	O
it	O
is	O
out	O
of	O
bullets	O
,	O
it	O
will	O
find	O
a	O
cover	O
object	O
and	O
hide	O
behind	O
it	O
until	O
it	O
has	O
reloaded	O
.	O
</s>
<s>
Actions	O
like	O
these	O
make	O
the	O
AI	B-Application
seem	O
more	O
human	O
.	O
</s>
<s>
Another	O
side-effect	O
of	O
combat	O
AI	B-Application
occurs	O
when	O
two	O
AI-controlled	O
characters	O
encounter	O
each	O
other	O
;	O
first	O
popularized	O
in	O
the	O
id	O
Software	O
game	O
Doom	B-Application
,	O
so-called	O
'	O
monster	O
infighting	O
 '	O
can	O
break	O
out	O
in	O
certain	O
situations	O
.	O
</s>
<s>
Specifically	O
,	O
AI	B-Application
agents	O
that	O
are	O
programmed	O
to	O
respond	O
to	O
hostile	O
attacks	O
will	O
sometimes	O
attack	O
each	O
other	O
if	O
their	O
cohort	O
's	O
attacks	O
land	O
too	O
close	O
to	O
them	O
.	O
</s>
<s>
In	O
the	O
case	O
of	O
Doom	B-Application
,	O
published	O
gameplay	O
manuals	O
even	O
suggest	O
taking	O
advantage	O
of	O
monster	O
infighting	O
in	O
order	O
to	O
survive	O
certain	O
levels	O
and	O
difficulty	O
settings	O
.	O
</s>
<s>
Game	B-Application
AI	I-Application
often	O
amounts	O
to	O
pathfinding	B-Algorithm
and	O
finite	B-Architecture
state	I-Architecture
machines	I-Architecture
.	O
</s>
<s>
Pathfinding	B-Algorithm
gets	O
the	O
AI	B-Application
from	O
point	O
A	O
to	O
point	O
B	O
,	O
usually	O
in	O
the	O
most	O
direct	O
way	O
possible	O
.	O
</s>
<s>
State	B-Architecture
machines	I-Architecture
permit	O
transitioning	O
between	O
different	O
behaviors	O
.	O
</s>
<s>
The	O
Monte	B-Application
Carlo	I-Application
tree	I-Application
search	I-Application
method	O
provides	O
a	O
more	O
engaging	O
game	O
experience	O
by	O
creating	O
additional	O
obstacles	O
for	O
the	O
player	O
to	O
overcome	O
.	O
</s>
<s>
The	O
MCTS	O
consists	O
of	O
a	O
tree	O
diagram	O
in	O
which	O
the	O
AI	B-Application
essentially	O
plays	O
tic-tac-toe	O
.	O
</s>
<s>
Academic	O
AI	B-Application
may	O
play	O
a	O
role	O
within	O
Game	B-Application
AI	I-Application
,	O
outside	O
the	O
traditional	O
concern	O
of	O
controlling	O
NPC	O
behavior	O
.	O
</s>
<s>
Game	B-Application
AI	I-Application
may	O
also	O
help	O
deduce	O
player	O
intent	O
(	O
such	O
as	O
gesture	B-General_Concept
recognition	I-General_Concept
)	O
.	O
</s>
<s>
AI	B-Application
methods	O
can	O
generate	O
new	O
content	O
or	O
interactive	O
stories	O
.	O
</s>
<s>
Data	B-Application
mining	I-Application
on	O
user	O
behavior	O
:	O
This	O
allows	O
game	O
designers	O
to	O
explore	O
how	O
people	O
use	O
the	O
game	O
,	O
what	O
parts	O
they	O
play	O
most	O
,	O
and	O
what	O
causes	O
them	O
to	O
stop	O
playing	O
,	O
allowing	O
developers	O
to	O
tune	O
gameplay	O
or	O
improve	O
monetization	O
.	O
</s>
<s>
Rather	O
than	O
procedural	O
generation	O
,	O
some	O
researchers	O
have	O
used	O
generative	B-Algorithm
adversarial	I-Algorithm
networks	I-Algorithm
(	O
GANs	O
)	O
to	O
create	O
new	O
content	O
.	O
</s>
<s>
In	O
2018	O
researchers	O
at	O
Cornwall	O
University	O
trained	O
a	O
GAN	O
on	O
a	O
thousand	O
human-created	O
levels	O
for	O
DOOM	B-Application
(	O
1993	O
)	O
;	O
following	O
training	O
,	O
the	O
neural	O
net	O
prototype	O
was	O
able	O
to	O
design	O
new	O
playable	O
levels	O
on	O
its	O
own	O
.	O
</s>
<s>
Similarly	O
,	O
researchers	O
at	O
the	O
University	O
of	O
California	O
prototyped	O
a	O
GAN	O
to	O
generate	O
levels	O
for	O
Super	B-Application
Mario	I-Application
.	O
</s>
<s>
In	O
2020	O
Nvidia	O
displayed	O
a	O
GAN-created	O
clone	O
of	O
Pac-Man	B-Application
;	O
the	O
GAN	O
learned	O
how	O
to	O
recreate	O
the	O
game	O
by	O
watching	O
50,000	O
(	O
mostly	O
bot-generated	O
)	O
playthroughs	O
.	O
</s>
<s>
In	O
the	O
context	O
of	O
artificial	B-Application
intelligence	I-Application
in	I-Application
video	I-Application
games	I-Application
,	O
cheating	O
refers	O
to	O
the	O
programmer	O
giving	O
agents	O
actions	O
and	O
access	O
to	O
information	O
that	O
would	O
be	O
unavailable	O
to	O
the	O
player	O
in	O
the	O
same	O
situation	O
.	O
</s>
<s>
Believing	O
that	O
the	O
Atari	B-Device
8-bit	I-Device
could	O
not	O
compete	O
against	O
a	O
human	O
player	O
,	O
Chris	O
Crawford	O
did	O
not	O
fix	O
a	O
bug	O
in	O
Eastern	B-Application
Front	I-Application
(	O
1941	O
)	O
that	O
benefited	O
the	O
computer-controlled	O
Russian	O
side	O
.	O
</s>
<s>
Computer	O
Gaming	O
World	O
in	O
1994	O
reported	O
that	O
"	O
It	O
is	O
a	O
well-known	O
fact	O
that	O
many	O
AIs	B-Application
'	O
cheat	O
 '	O
(	O
or	O
,	O
at	O
least	O
,	O
'	O
fudge	O
 '	O
)	O
in	O
order	O
to	O
be	O
able	O
to	O
keep	O
up	O
with	O
human	O
players	O
"	O
.	O
</s>
<s>
Common	O
variations	O
include	O
giving	O
AIs	B-Application
higher	O
speeds	O
in	O
racing	O
games	O
to	O
catch	O
up	O
to	O
the	O
player	O
or	O
spawning	O
them	O
in	O
advantageous	O
positions	O
in	O
first-person	O
shooters	O
.	O
</s>
<s>
The	O
use	O
of	O
cheating	O
in	O
AI	B-Application
shows	O
the	O
limitations	O
of	O
the	O
"	O
intelligence	O
"	O
achievable	O
artificially	O
;	O
generally	O
speaking	O
,	O
in	O
games	O
where	O
strategic	O
creativity	O
is	O
important	O
,	O
humans	O
could	O
easily	O
beat	O
the	O
AI	B-Application
after	O
a	O
minimum	O
of	O
trial	O
and	O
error	O
if	O
it	O
were	O
not	O
for	O
this	O
advantage	O
.	O
</s>
<s>
While	O
cheating	O
refers	O
only	O
to	O
privileges	O
given	O
specifically	O
to	O
the	O
AI	B-Application
—	O
it	O
does	O
not	O
include	O
the	O
inhuman	O
swiftness	O
and	O
precision	O
natural	O
to	O
a	O
computer	O
—	O
a	O
player	O
might	O
call	O
the	O
computer	O
's	O
inherent	O
advantages	O
"	O
cheating	O
"	O
if	O
they	O
result	O
in	O
the	O
agent	O
acting	O
unlike	O
a	O
human	O
player	O
.	O
</s>
<s>
Sid	O
Meier	O
stated	O
that	O
he	O
omitted	O
multiplayer	O
alliances	O
in	O
Civilization	B-Application
because	O
he	O
found	O
that	O
the	O
computer	O
was	O
almost	O
as	O
good	O
as	O
humans	O
in	O
using	O
them	O
,	O
which	O
caused	O
players	O
to	O
think	O
that	O
the	O
computer	O
was	O
cheating	O
.	O
</s>
<s>
Developers	O
say	O
that	O
most	O
game	B-Application
AIs	I-Application
are	O
honest	O
but	O
they	O
dislike	O
players	O
erroneously	O
complaining	O
about	O
"	O
cheating	O
"	O
AI	B-Application
.	O
</s>
<s>
In	O
the	O
1996	O
game	O
Creatures	B-Application
,	O
the	O
user	O
"	O
hatches	O
"	O
small	O
furry	O
animals	O
and	O
teaches	O
them	O
how	O
to	O
behave	O
.	O
</s>
<s>
These	O
"	O
Norns	O
"	O
can	O
talk	O
,	O
feed	O
themselves	O
,	O
and	O
protect	O
themselves	O
against	O
vicious	O
creatures	B-Application
.	O
</s>
<s>
Neural	O
networks	O
are	O
used	O
by	O
the	O
creatures	B-Application
to	O
learn	O
what	O
to	O
do	O
.	O
</s>
<s>
The	O
game	O
is	O
regarded	O
as	O
a	O
breakthrough	O
in	O
artificial	O
life	O
research	O
,	O
which	O
aims	O
to	O
model	O
the	O
behavior	O
of	O
creatures	B-Application
interacting	O
with	O
their	O
environment	O
.	O
</s>
<s>
The	O
underlying	O
"	O
behavior	O
tree	O
"	O
technology	O
has	O
become	O
very	O
popular	O
in	O
the	O
games	O
industry	O
since	O
Halo	B-Application
2	I-Application
.	O
</s>
<s>
has	O
player	O
characters	O
engage	O
a	O
battalion	O
of	O
cloned	O
super-soldiers	O
,	O
robots	O
and	O
paranormal	O
creatures	B-Application
.	O
</s>
<s>
The	O
AI	B-Application
uses	O
a	O
planner	O
to	O
generate	O
context-sensitive	O
behaviors	O
,	O
the	O
first	O
time	O
in	O
a	O
mainstream	O
game	O
.	O
</s>
<s>
In	O
addition	O
,	O
the	O
AI	B-Application
is	O
also	O
capable	O
of	O
performing	O
flanking	O
maneuvers	O
,	O
using	O
suppressing	O
fire	O
,	O
throwing	O
grenades	O
to	O
flush	O
the	O
player	O
out	O
of	O
cover	O
,	O
and	O
even	O
playing	O
dead	O
.	O
</s>
<s>
The	O
survival	O
horror	O
series	O
S.T.A.L.K.E.R.	B-Application
</s>
<s>
(	O
2007	O
–	O
)	O
confronts	O
the	O
player	O
with	O
man-made	O
experiments	O
,	O
military	O
soldiers	O
,	O
and	O
mercenaries	O
known	O
as	O
Stalkers	B-Application
.	O
</s>
<s>
The	O
2010	O
real-time	O
strategy	O
game	O
StarCraft	B-Application
II	I-Application
:	I-Application
Wings	I-Application
of	I-Application
Liberty	I-Application
gives	O
the	O
player	O
control	O
of	O
one	O
of	O
three	O
factions	O
in	O
a	O
1v1	O
,	O
2v2	O
,	O
or	O
3v3	O
battle	O
arena	O
.	O
</s>
<s>
Players	O
can	O
play	O
against	O
multiple	O
different	O
levels	O
of	O
AI	B-Application
difficulty	O
ranging	O
from	O
very	O
easy	O
to	O
Cheater	O
3	O
(	O
insane	O
)	O
.	O
</s>
<s>
The	O
AI	B-Application
is	O
able	O
to	O
cheat	O
at	O
the	O
difficulty	O
Cheater	O
1	O
(	O
vision	O
)	O
,	O
where	O
it	O
can	O
see	O
units	O
and	O
bases	O
when	O
a	O
player	O
in	O
the	O
same	O
situation	O
could	O
not	O
.	O
</s>
<s>
Cheater	O
2	O
gives	O
the	O
AI	B-Application
extra	O
resources	O
,	O
while	O
Cheater	O
3	O
gives	O
an	O
extensive	O
advantage	O
over	O
its	O
opponent	O
.	O
</s>
