<s>
Chase	O
is	O
a	O
turn-based	O
computer	O
game	O
in	O
which	O
players	O
are	O
tasked	O
with	O
escaping	O
from	O
robots	B-Algorithm
programmed	O
to	O
pursue	O
and	O
kill	O
them	O
.	O
</s>
<s>
The	O
player	O
attempts	O
to	O
destroy	O
the	O
robots	B-Algorithm
by	O
moving	O
in	O
such	O
a	O
way	O
that	O
the	O
robots	B-Algorithm
collide	O
with	O
each	O
other	O
or	O
other	O
obstacles	O
.	O
</s>
<s>
The	O
basic	O
concept	O
has	O
been	O
part	O
of	O
games	O
stretching	O
into	O
the	O
1970s	O
,	O
and	O
is	O
among	O
the	O
earliest	O
of	O
the	O
"	O
standards	O
"	O
for	O
microcomputer	B-Architecture
platforms	O
.	O
</s>
<s>
and	O
Zombies	O
,	O
Daleks	B-Device
on	O
MacOS	B-Application
and	O
robots	B-Algorithm
on	O
Unix	B-Application
.	O
</s>
<s>
The	O
original	O
author	O
of	O
the	O
game	O
remains	O
unknown	O
,	O
but	O
it	O
is	O
highly	O
likely	O
it	O
started	O
on	O
the	O
DTSS	B-Operating_System
system	O
at	O
Dartmouth	O
College	O
in	O
the	O
early	O
1970s	O
.	O
</s>
<s>
The	O
first	O
public	O
versions	O
appeared	O
in	O
Creative	B-General_Concept
Computing	I-General_Concept
magazine	O
in	O
early	O
1976	O
and	O
a	O
variety	O
of	O
modified	O
versions	O
appeared	O
over	O
the	O
next	O
few	O
years	O
.	O
</s>
<s>
Daleks	B-Device
and	O
robots	B-Algorithm
both	O
appeared	O
in	O
1984	O
,	O
leading	O
to	O
another	O
wave	O
of	O
similar	O
versions	O
.	O
</s>
<s>
The	O
objective	O
of	O
the	O
game	O
is	O
to	O
escape	O
from	O
a	O
number	O
of	O
robots	B-Algorithm
,	O
which	O
have	O
been	O
programmed	O
to	O
kill	O
the	O
player	O
.	O
</s>
<s>
In	O
some	O
derivative	O
versions	O
,	O
such	O
as	O
the	O
GNOME	B-Application
version	O
,	O
the	O
player	O
starts	O
at	O
the	O
centre	O
of	O
the	O
grid	O
.	O
</s>
<s>
The	O
robots	B-Algorithm
start	O
at	O
randomly	O
selected	O
locations	O
on	O
the	O
grid	O
.	O
</s>
<s>
Every	O
time	O
the	O
player	O
character	O
moves	O
a	O
square	O
in	O
any	O
direction	O
(	O
horizontally	O
,	O
vertically	O
,	O
or	O
diagonally	O
)	O
,	O
each	O
robot	B-Algorithm
moves	O
one	O
square	O
closer	O
to	O
their	O
new	O
location	O
,	O
in	O
whichever	O
direction	O
is	O
the	O
shortest	O
path	O
.	O
</s>
<s>
If	O
the	O
player	O
character	O
collides	O
with	O
a	O
robot	B-Algorithm
,	O
they	O
die	O
and	O
the	O
game	O
ends	O
.	O
</s>
<s>
The	O
player	O
attempts	O
to	O
survive	O
by	O
causing	O
the	O
robots	B-Algorithm
to	O
kill	O
themselves	O
by	O
colliding	O
with	O
other	O
objects	O
on	O
the	O
map	O
.	O
</s>
<s>
In	O
earlier	O
versions	O
derived	O
from	O
Chase	O
!,	O
there	O
are	O
a	O
number	O
of	O
deadly	O
objects	O
on	O
the	O
map	O
that	O
will	O
kill	O
either	O
the	O
robots	B-Algorithm
or	O
the	O
player	O
.	O
</s>
<s>
In	O
later	O
versions	O
derived	O
from	O
robots	B-Algorithm
,	O
the	O
map	O
is	O
initially	O
clear	O
and	O
these	O
hazards	O
are	O
created	O
when	O
two	O
robots	B-Algorithm
collide	O
to	O
create	O
a	O
pile	O
of	O
rubble	O
.	O
</s>
<s>
In	O
either	O
case	O
,	O
the	O
player	O
is	O
attempting	O
to	O
move	O
in	O
such	O
a	O
way	O
to	O
cause	O
the	O
robots	B-Algorithm
to	O
collide	O
with	O
each	O
other	O
or	O
stationary	O
obstacles	O
.	O
</s>
<s>
The	O
player	O
can	O
also	O
teleport	B-General_Concept
into	O
a	O
randomly	O
selected	O
location	O
in	O
cases	O
where	O
escape	O
is	O
otherwise	O
impossible	O
.	O
</s>
<s>
Teleportation	B-General_Concept
counts	O
as	O
a	O
move	O
,	O
and	O
the	O
robots	B-Algorithm
will	O
respond	O
by	O
moving	O
towards	O
the	O
new	O
location	O
.	O
</s>
<s>
Because	O
the	O
location	O
is	O
randomly	O
selected	O
,	O
it	O
is	O
possible	O
that	O
the	O
player	O
teleports	O
right	O
into	O
the	O
path	O
of	O
a	O
robot	B-Algorithm
.	O
</s>
<s>
In	O
some	O
versions	O
of	O
the	O
game	O
,	O
there	O
is	O
a	O
"	O
safe	O
teleport	B-General_Concept
"	O
feature	O
which	O
the	O
player	O
may	O
use	O
a	O
limited	O
number	O
of	O
times	O
(	O
for	O
instance	O
once	O
per	O
level	O
)	O
and	O
there	O
may	O
also	O
be	O
a	O
close-range	O
weapon	O
which	O
kills	O
all	O
robots	B-Algorithm
within	O
the	O
immediate	O
vicinity	O
,	O
the	O
use	O
of	O
which	O
would	O
be	O
limited	O
in	O
a	O
similar	O
way	O
.	O
</s>
<s>
It	O
otherwise	O
acts	O
like	O
the	O
other	O
robots	B-Algorithm
.	O
</s>
<s>
The	O
game	O
is	O
won	O
when	O
all	O
of	O
the	O
robots	B-Algorithm
are	O
destroyed	O
.	O
</s>
<s>
In	O
modern	O
versions	O
,	O
this	O
normally	O
results	O
in	O
the	O
game	O
proceeding	O
to	O
another	O
level	O
with	O
more	O
robots	B-Algorithm
.	O
</s>
<s>
Traditionally	O
,	O
the	O
number	O
of	O
robots	B-Algorithm
increases	O
by	O
ten	O
each	O
level	O
.	O
</s>
<s>
Chase	O
was	O
originally	O
written	O
in	O
Dartmouth	B-Language
BASIC	I-Language
on	O
the	O
DTSS	B-Operating_System
system	O
at	O
Dartmouth	O
College	O
.	O
</s>
<s>
The	O
Jan-Feb	O
1976	O
issue	O
of	O
Creative	B-General_Concept
Computing	I-General_Concept
contains	O
a	O
version	O
of	O
this	O
original	O
code	O
ported	O
to	O
the	O
Honeywell	B-Device
6000	I-Device
series	I-Device
by	O
Bill	O
Cotter	O
.	O
</s>
<s>
It	O
was	O
republished	O
in	O
1979	O
's	O
More	O
BASIC	O
Computer	O
Games	O
,	O
at	O
that	O
time	O
adding	O
a	O
note	O
suggesting	O
the	O
original	O
author	O
was	O
Mac	O
Oglesby	O
,	O
a	O
prolific	O
game	O
author	O
of	O
Dartmouth	B-Language
BASIC	I-Language
games	O
from	O
the	O
mainframe	O
era	O
.	O
</s>
<s>
A	O
series	O
of	O
relatively	O
direct	O
copies	O
of	O
this	O
game	O
appeared	O
in	O
computer	O
magazines	O
of	O
the	O
era	O
,	O
including	O
one	O
for	O
the	O
SWCP	O
4k	O
BASIC	O
,	O
and	O
a	O
graphical	O
version	O
using	O
the	O
VDM-1	B-Device
card	O
for	O
S-100	B-Architecture
bus	I-Architecture
machines	O
.	O
</s>
<s>
It	O
was	O
also	O
ported	O
to	O
the	O
PLATO	B-Operating_System
system	I-Operating_System
's	O
TUTOR	B-Language
language	O
on	O
the	O
MODCOMP	O
IV	O
as	O
HiVolts	O
.	O
</s>
<s>
One	O
such	O
version	O
appears	O
in	O
Announcing	O
:	O
Computer	O
Games	O
for	O
the	O
TRS-80	B-Device
,	O
which	O
added	O
another	O
enemy	O
,	O
the	O
tank	O
,	O
and	O
limited	O
the	O
player	O
to	O
two	O
teleports	O
per	O
match	O
.	O
</s>
<s>
was	O
also	O
sold	O
by	O
Sublogic	O
as	O
early	O
as	O
1982	O
,	O
which	O
added	O
a	O
real-time	O
option	O
that	O
caused	O
the	O
robots	B-Algorithm
to	O
move	O
even	O
if	O
the	O
user	O
did	O
n't	O
.	O
</s>
<s>
A	O
review	O
of	O
this	O
version	O
in	O
Creative	B-General_Concept
Computing	I-General_Concept
once	O
again	O
attributed	O
the	O
original	O
to	O
Mac	O
Oglesby	O
.	O
</s>
<s>
known	O
as	O
Robot	B-Algorithm
Minefield	O
was	O
released	O
in	O
1983	O
by	O
Tim	O
Hartnell	O
and	O
Nathan	O
Butcher	O
.	O
</s>
<s>
In	O
addition	O
,	O
the	O
player	O
could	O
only	O
move	O
in	O
four	O
directions	O
(	O
North	O
,	O
South	O
,	O
East	O
,	O
West	O
)	O
while	O
the	O
robots	B-Algorithm
had	O
the	O
ability	O
to	O
move	O
diagonally	O
.	O
</s>
<s>
The	O
game	O
was	O
played	O
in	O
real	O
time	O
;	O
as	O
the	O
player	O
pondered	O
his	O
move	O
,	O
the	O
robots	B-Algorithm
would	O
continue	O
converging	O
toward	O
him	O
.	O
</s>
<s>
The	O
Unix-based	O
robots	B-Algorithm
was	O
developed	O
by	O
Allan	O
R	O
.	O
Black	O
in	O
November	O
,	O
1984	O
.	O
</s>
<s>
In	O
May	O
1985	O
,	O
it	O
was	O
posted	O
to	O
the	O
Usenet	B-Application
newsgroup	O
net.sources.games	O
.	O
</s>
<s>
It	O
was	O
then	O
ported	O
to	O
the	O
Berkeley	B-Operating_System
Software	I-Operating_System
Distribution	I-Operating_System
by	O
Ken	O
Arnold	O
.	O
</s>
<s>
The	O
BSD	B-Operating_System
Unix	I-Operating_System
version	O
of	O
robots	B-Algorithm
first	O
appeared	O
in	O
the	O
4.3BSD	B-Operating_System
software	O
release	O
in	O
June	O
1986	O
.	O
</s>
