<s>
Day	B-Application
of	I-Application
Defeat	I-Application
is	O
a	O
team-based	O
multiplayer	O
first-person	O
shooter	O
video	O
game	O
set	O
in	O
the	O
European	O
theatre	O
of	O
World	O
War	O
II	O
on	O
the	O
Western	O
front	O
.	O
</s>
<s>
Originally	O
a	O
modification	O
of	O
the	O
1998	O
game	O
Half-Life	B-Application
,	O
the	O
rights	O
of	O
the	O
modification	O
were	O
purchased	O
by	O
Valve	O
and	O
released	O
as	O
a	O
full	O
retail	O
title	O
in	O
2003	O
.	O
</s>
<s>
Set	O
in	O
the	O
midst	O
of	O
World	O
War	O
II	O
,	O
Day	B-Application
of	I-Application
Defeat	I-Application
includes	O
no	O
single-player	O
campaign	O
,	O
with	O
focus	O
left	O
only	O
on	O
the	O
game	O
's	O
multiplayer	O
aspects	O
.	O
</s>
<s>
An	O
official	O
remake	O
of	O
the	O
game	O
,	O
Day	B-Application
of	I-Application
Defeat	I-Application
:	I-Application
Source	I-Application
,	O
was	O
released	O
by	O
Valve	O
in	O
2005	O
.	O
</s>
<s>
Day	B-Application
of	I-Application
Defeat	I-Application
is	O
a	O
multiplayer	O
first-person	O
shooter	O
that	O
simulates	O
squad-level	O
infantry	B-Protocol
combat	O
between	O
the	O
adversaries	O
of	O
World	O
War	O
II	O
's	O
European	O
Theatre	O
;	O
the	O
Allies	O
and	O
the	O
Axis	O
powers	O
.	O
</s>
<s>
Day	B-Application
of	I-Application
Defeat	I-Application
's	O
initial	O
retail	O
offering	O
included	O
fifteen	O
maps	O
,	O
each	O
depicting	O
different	O
scenarios	O
with	O
variation	O
in	O
size	O
and	O
thematic	O
locations	O
.	O
</s>
<s>
The	O
game	O
also	O
features	O
a	O
Glider	O
mission	O
wherein	O
the	O
American	O
101st	O
Airborne	O
lands	O
in	O
a	O
WACO	O
Glider	O
and	O
destroys	O
such	O
objectives	O
as	O
a	O
radio	O
antenna	O
and	O
Flak	O
88	O
mm	O
gun	O
anti-aircraft	B-Application
gun	O
.	O
</s>
<s>
Day	B-Application
of	I-Application
Defeat	I-Application
began	O
as	O
a	O
third-party	O
Half-Life	B-Application
modification	O
in	O
2000	O
.	O
</s>
<s>
While	O
the	O
first	O
versions	O
of	O
Day	B-Application
of	I-Application
Defeat	I-Application
were	O
distributed	O
over	O
the	O
internet	O
at	O
no	O
cost	O
,	O
the	O
rights	O
to	O
the	O
game	O
were	O
later	O
purchased	O
by	O
Valve	O
and	O
the	O
modding	O
team	O
hired	O
.	O
</s>
<s>
At	O
the	O
end	O
of	O
July	O
2004	O
,	O
Valve	O
shut	O
down	O
the	O
World	O
Opponent	O
Network	O
(	O
WON	O
)	O
in	O
favor	O
of	O
their	O
digital	O
distribution	O
service	O
Steam	B-Application
.	O
</s>
<s>
All	O
servers	O
using	O
the	O
former	O
were	O
shut	O
down	O
and	O
migrated	O
to	O
Steam	B-Application
,	O
forcing	O
players	O
to	O
use	O
the	O
new	O
storefront	O
to	O
access	O
Day	B-Application
of	I-Application
Defeat	I-Application
.	O
</s>
<s>
In	O
2013	O
,	O
Valve	O
released	O
an	O
update	O
for	O
Day	B-Application
of	I-Application
Defeat	I-Application
,	O
alongside	O
other	O
GoldSrc	B-Application
games	O
developed	O
by	O
Valve	O
,	O
which	O
included	O
versions	O
of	O
the	O
game	O
for	O
Mac	B-Application
OS	I-Application
X	I-Application
and	O
Linux	B-Application
.	O
</s>
<s>
Day	B-Application
of	I-Application
Defeat	I-Application
received	O
"	O
generally	O
favorable	O
reviews	O
"	O
according	O
to	O
the	O
review	B-Application
aggregation	I-Application
website	O
Metacritic	O
.	O
</s>
<s>
Reviewers	O
also	O
praised	O
Day	B-Application
of	I-Application
Defeat	I-Application
for	O
its	O
promotion	O
of	O
teamwork	O
through	O
purposefully	O
tight	O
corridors	O
that	O
force	O
players	O
to	O
cooperate	O
,	O
lest	O
they	O
be	O
killed	O
by	O
an	O
enemy	O
outside	O
their	O
field	O
of	O
vision	O
.	O
</s>
<s>
Both	O
GameSpy	O
and	O
GameSpot	O
levied	O
criticism	O
against	O
the	O
game	O
for	O
its	O
sub-par	O
visuals	O
and	O
"	O
downright	O
ugly	O
"	O
color	O
palette	O
,	O
blaming	O
the	O
aging	O
GoldSrc	B-Application
engine	I-Application
for	O
the	O
aesthetic	O
issues	O
.	O
</s>
<s>
Many	O
reviewers	O
drew	O
parallels	O
between	O
Day	B-Application
of	I-Application
Defeat	I-Application
and	O
Battlefield	B-Application
1942	I-Application
,	O
the	O
latter	O
of	O
which	O
had	O
been	O
released	O
only	O
six	O
months	O
prior	O
to	O
the	O
former	O
.	O
</s>
<s>
Both	O
games	O
were	O
set	O
in	O
World	O
War	O
II	O
and	O
featured	O
gameplay	O
that	O
was	O
heavily	O
reliant	O
on	O
their	O
respective	O
class-based	O
systems	O
,	O
which	O
lead	O
reviewers	O
to	O
make	O
direct	O
comparisons	O
between	O
the	O
two	O
in	O
their	O
reviews	O
of	O
Day	B-Application
of	I-Application
Defeat	I-Application
.	O
</s>
<s>
PC	O
Gamer	O
US	O
awarded	O
Day	B-Application
of	I-Application
Defeat	I-Application
its	O
2001	O
"	O
Mod	O
of	O
the	O
Year	O
"	O
prize	O
.	O
</s>
<s>
The	O
editors	O
wrote	O
,	O
"	O
Made	O
by	O
amateur	O
developers	O
not	O
yet	O
of	O
American	O
drinking	O
age	O
,	O
Day	B-Application
of	I-Application
Defeat	I-Application
absorbed	O
entire	O
weeks	O
of	O
office	O
LAN	O
play.	O
"	O
</s>
<s>
Day	B-Application
of	I-Application
Defeat	I-Application
was	O
followed	O
by	O
Day	B-Application
of	I-Application
Defeat	I-Application
:	I-Application
Source	I-Application
,	O
a	O
remake	O
of	O
the	O
game	O
that	O
runs	O
on	O
Valve	O
's	O
Source	B-Application
engine	I-Application
.	O
</s>
<s>
The	O
Source	O
remake	O
included	O
significant	O
changes	O
to	O
Day	B-Application
of	I-Application
Defeat	I-Application
's	O
gameplay	O
,	O
new	O
maps	O
,	O
updated	O
graphics	O
,	O
and	O
improved	O
physics	O
.	O
</s>
<s>
Post-release	O
,	O
the	O
game	O
was	O
supported	O
by	O
Valve	O
with	O
a	O
number	O
of	O
subsequent	O
updates	O
,	O
including	O
versions	O
of	O
the	O
game	O
for	O
OS	B-Operating_System
X	I-Operating_System
and	O
Linux	B-Application
released	O
in	O
2010	O
and	O
2013	O
respectively	O
.	O
</s>
