<s>
Empire	O
is	O
the	O
name	O
of	O
a	O
computer	O
game	O
written	O
for	O
the	O
PLATO	B-Operating_System
system	I-Operating_System
in	O
1973	O
.	O
</s>
<s>
It	O
is	O
significant	O
for	O
being	O
quite	O
probably	O
the	O
first	O
networked	B-Architecture
multiplayer	O
arena	O
shooter-style	O
game	O
.	O
</s>
<s>
It	O
may	O
also	O
be	O
the	O
first	O
networked	B-Architecture
multiplayer	O
action	O
game	O
(	O
although	O
Maze	B-Application
War	I-Application
is	O
another	O
possibility	O
for	O
this	O
distinction	O
)	O
.	O
</s>
<s>
Although	O
PLATO	B-Operating_System
terminals	I-Operating_System
had	O
touch	O
panels	O
,	O
they	O
did	O
not	O
have	O
mice	O
,	O
and	O
all	O
control	O
in	O
the	O
game	O
is	O
via	O
typing	O
.	O
</s>
<s>
PLATO	B-Operating_System
terminals	I-Operating_System
had	O
512	O
by	O
512	O
pixel	B-Algorithm
monochrome	O
vector	O
CRT	O
display	O
screens	O
,	O
and	O
could	O
use	O
downloadable	O
character	O
sets	O
to	O
display	O
graphics	O
.	O
</s>
<s>
Players	O
dogfight	B-Device
each	O
other	O
,	O
destroy	O
enemy	O
armies	O
by	O
bombing	O
them	O
,	O
beam	O
up	O
friendly	O
armies	O
to	O
transport	O
them	O
,	O
and	O
beam	O
down	O
armies	O
to	O
take	O
over	O
planets	O
.	O
</s>
<s>
Original	O
PLATO	B-Operating_System
terminals	I-Operating_System
were	O
connected	O
to	O
the	O
host	O
system	O
with	O
a	O
1200	O
baud	O
connection	O
,	O
and	O
the	O
host	O
computers	O
were	O
quite	O
slow	O
by	O
current	O
standards	O
.	O
</s>
<s>
Game	O
play	O
was	O
also	O
affected	O
by	O
the	O
Plato	B-Operating_System
system	I-Operating_System
's	O
context	B-Operating_System
switching	I-Operating_System
CPU	B-Device
scheduling	O
algorithm	O
.	O
</s>
<s>
Plato	B-Operating_System
attempted	O
fair	O
allocation	O
of	O
the	O
limited	O
CPU	B-Device
resources	O
available	O
by	O
calculating	O
for	O
each	O
user	O
the	O
ratio	O
of	O
the	O
total	O
CPU	B-Device
time	O
used	O
during	O
a	O
session	O
divided	O
by	O
the	O
total	O
duration	O
of	O
the	O
session	O
.	O
</s>
<s>
The	O
system	O
would	O
grant	O
extra	O
CPU	B-Device
time	O
to	O
sessions	O
with	O
lower	O
CPU	B-Device
time/session	O
duration	O
ratios	O
at	O
the	O
expense	O
of	O
sessions	O
with	O
higher	O
CPU	B-Device
time/session	O
duration	O
ratios	O
.	O
</s>
<s>
Empire	O
players	O
would	O
obtain	O
more	O
CPU	B-Device
for	O
game	O
play	O
by	O
logging	O
in	O
hours	O
before	O
commencing	O
game	O
play	O
and	O
leaving	O
the	O
session	O
idle	O
,	O
thereby	O
accumulating	O
a	O
very	O
low	O
CPU	B-Device
used/session	O
duration	O
ratio	O
that	O
would	O
ensure	O
high	O
CPU	B-Device
allocation	O
to	O
the	O
player	O
during	O
game	O
play	O
.	O
</s>
<s>
Players	O
who	O
did	O
not	O
engage	O
in	O
this	O
practice	O
were	O
burdened	O
with	O
poor	O
game	O
responsiveness	B-Application
due	O
to	O
relative	O
lack	O
of	O
CPU	B-Device
.	O
</s>
<s>
Silas	O
Warner	O
helped	O
out	O
by	O
providing	O
Daleske	O
with	O
disk	O
space	O
(	O
known	O
as	O
"	O
lesson	O
space	O
"	O
in	O
the	O
PLATO	B-Operating_System
environment	O
)	O
.	O
</s>
<s>
This	O
version	O
of	O
the	O
game	O
,	O
with	O
a	O
few	O
minor	O
modifications	O
(	O
newer	O
looping	O
constructs	O
replace	O
branches	O
,	O
and	O
a	O
timing	O
issue	O
has	O
been	O
corrected	O
)	O
may	O
still	O
be	O
played	O
on	O
the	O
Cyber1	O
PLATO	B-Operating_System
system	I-Operating_System
.	O
</s>
<s>
Usage	O
logs	O
from	O
the	O
PLATO	B-Operating_System
system	I-Operating_System
at	O
the	O
Computer-based	B-Operating_System
Education	I-Operating_System
Research	I-Operating_System
Laboratory	I-Operating_System
(	O
CERL	O
)	O
at	O
UIUC	O
indicate	O
that	O
between	O
1978	O
and	O
1985	O
,	O
users	O
spent	O
about	O
300,000	O
hours	O
playing	O
Empire	O
.	O
</s>
<s>
Empire	O
inspired	O
many	O
derivative	O
games	O
,	O
including	O
Trek82	O
,	O
Trek83	O
,	O
ROBOTREK	O
,	O
Xtrek	O
,	O
and	O
Netrek	B-Application
.	O
</s>
<s>
Empire	O
was	O
adapted	O
with	O
emailed	O
permission	O
from	O
Chuck	O
Miller	O
&	O
Gary	O
Fritz	O
for	O
the	O
Apple	B-Device
II	I-Device
computer	O
by	O
Robert	O
Woodhead	O
of	O
Wizardry	B-Device
fame	O
as	O
a	O
game	O
called	O
Galactic	O
Attack	O
.	O
</s>
<s>
PLATO	B-Operating_System
Conquest	O
(	O
based	O
on	O
Empire	O
I	O
)	O
can	O
still	O
(	O
as	O
of	O
the	O
late	O
1990s	O
)	O
be	O
found	O
on	O
the	O
NovaNET	O
PLATO	B-Operating_System
systems	I-Operating_System
.	O
</s>
<s>
In	O
1982	O
Jef	O
Poskanzer	O
wrote	O
a	O
version	O
of	O
the	O
space-battle	O
Empire	O
game	O
called	O
Conquest	O
for	O
VAX/VMS	B-Operating_System
computers	O
.	O
</s>
