<s>
Dota	B-Operating_System
is	O
a	O
series	O
of	O
strategy	B-Application
video	I-Application
games	I-Application
.	O
</s>
<s>
The	O
series	O
began	O
in	O
2003	O
with	O
the	O
release	O
of	O
Defense	B-Operating_System
of	I-Operating_System
the	I-Operating_System
Ancients	I-Operating_System
(	O
DotA	B-Operating_System
)	O
,	O
a	O
fan-developed	O
multiplayer	O
online	B-Application
battle	O
arena	O
(	O
MOBA	O
)	O
mod	O
for	O
the	O
video	O
game	O
Warcraft	B-Application
III	I-Application
:	I-Application
Reign	I-Application
of	I-Application
Chaos	I-Application
and	O
its	O
expansion	O
,	O
The	B-Application
Frozen	I-Application
Throne	I-Application
.	O
</s>
<s>
Ownership	O
and	O
development	O
of	O
DotA	B-Operating_System
were	O
passed	O
on	O
multiple	O
times	O
since	O
its	O
initial	O
release	O
until	O
Valve	O
hired	O
the	O
mod	O
's	O
lead	O
designer	O
IceFrog	O
and	O
after	O
an	O
ongoing	O
legal	O
dispute	O
with	O
Blizzard	O
Entertainment	O
,	O
the	O
developer	O
of	O
Warcraft	B-Application
III	I-Application
,	O
brokered	O
a	O
deal	O
that	O
allowed	O
for	O
Valve	O
to	O
inherit	O
the	O
trademark	O
to	O
the	O
Dota	B-Operating_System
name	O
.	O
</s>
<s>
The	O
first	O
standalone	O
installment	O
in	O
the	O
series	O
,	O
Dota	B-Application
2	I-Application
,	O
was	O
released	O
by	O
Valve	O
in	O
July	O
2013	O
.	O
</s>
<s>
A	O
sequel	O
to	O
DotA	B-Operating_System
,	O
the	O
game	O
retains	O
the	O
same	O
gameplay	O
elements	O
as	O
its	O
predecessor	O
,	O
while	O
introducing	O
new	O
support	O
and	O
mechanics	O
,	O
as	O
well	O
as	O
a	O
setting	O
separate	O
from	O
the	O
Warcraft	B-Application
universe	O
.	O
</s>
<s>
Artifact	B-Application
,	O
a	O
digital	B-Application
collectible	I-Application
card	I-Application
game	I-Application
with	O
mechanics	O
inspired	O
by	O
Dota	B-Application
2	I-Application
,	O
was	O
released	O
in	O
2018	O
.	O
</s>
<s>
Dota	B-Application
Underlords	I-Application
,	O
an	O
auto	O
battler	O
based	O
on	O
the	O
community-created	O
Dota	B-Application
2	I-Application
mod	O
Dota	B-Operating_System
Auto	I-Operating_System
Chess	I-Operating_System
,	O
was	O
released	O
in	O
2020	O
.	O
</s>
<s>
The	O
original	O
DotA	B-Operating_System
mod	O
is	O
considered	O
one	O
of	O
the	O
most	O
popular	O
mods	O
of	O
all	O
time	O
,	O
with	O
tens	O
of	O
millions	O
of	O
players	O
and	O
a	O
consistent	O
presence	O
at	O
esports	O
tournaments	O
throughout	O
the	O
2000s	O
.	O
</s>
<s>
DotA	B-Operating_System
is	O
considered	O
a	O
catalyst	O
for	O
the	O
MOBA	O
genre	O
,	O
inspiring	O
developers	O
to	O
create	O
other	O
games	O
similar	O
to	O
it	O
.	O
</s>
<s>
Likewise	O
,	O
Dota	B-Application
2	I-Application
is	O
cited	O
as	O
one	O
of	O
the	O
greatest	O
video	O
games	O
of	O
all	O
time	O
,	O
with	O
an	O
esports	O
presence	O
hallmarked	O
by	O
record-breaking	O
prize	O
pools	O
that	O
culminate	O
in	O
the	O
annual	O
championship	O
known	O
as	O
The	O
International	O
.	O
</s>
<s>
The	O
spinoff	O
games	O
by	O
Valve	O
have	O
been	O
positively	O
received	O
,	O
although	O
Artifact	B-Application
was	O
considered	O
a	O
failure	O
as	O
a	O
large	O
majority	O
of	O
its	O
initial	O
player	O
base	O
was	O
lost	O
within	O
weeks	O
with	O
Valve	O
stopping	O
development	O
on	O
it	O
shortly	O
after	O
its	O
release	O
.	O
</s>
<s>
The	O
Dota	B-Operating_System
series	I-Operating_System
includes	O
four	O
games	O
that	O
are	O
centered	O
around	O
competitive	O
,	O
online	B-Application
multiplayer	O
gameplay	O
.	O
</s>
<s>
The	O
original	O
mod	O
,	O
Defense	B-Operating_System
of	I-Operating_System
the	I-Operating_System
Ancients	I-Operating_System
,	O
is	O
a	O
community-created	O
Warcraft	B-Application
III	I-Application
game	O
mode	O
developed	O
with	O
the	O
Warcraft	B-Application
III	I-Application
World	O
Editor	O
that	O
was	O
first	O
released	O
in	O
2003	O
.	O
</s>
<s>
The	O
franchise	O
name	O
,	O
"	O
Dota	B-Operating_System
"	O
,	O
is	O
derived	O
from	O
the	O
original	O
mod	O
's	O
acronym	O
,	O
DotA	B-Operating_System
.	O
</s>
<s>
Dota	B-Application
2	I-Application
,	O
its	O
standalone	O
installment	O
,	O
was	O
released	O
as	O
a	O
free-to-play	O
sequel	O
in	O
July	O
2013	O
.	O
</s>
<s>
The	O
first	O
spin-off	O
,	O
a	O
digital	B-Application
collectible	I-Application
card	I-Application
game	I-Application
called	O
Artifact	B-Application
,	O
was	O
released	O
in	O
November	O
2018	O
.	O
</s>
<s>
The	O
second	O
spin-off	O
,	O
an	O
auto	O
battler	O
called	O
Dota	B-Application
Underlords	I-Application
,	O
was	O
released	O
in	O
February	O
2020	O
.	O
</s>
<s>
The	O
main	O
installments	O
in	O
the	O
series	O
are	O
multiplayer	O
online	B-Application
battle	O
arena	O
games	O
,	O
where	O
the	O
player	O
assumes	O
control	O
over	O
a	O
single	O
character	O
-	O
a	O
"	O
hero	O
"	O
-	O
from	O
a	O
large	O
roster	O
of	O
characters	O
and	O
coordinates	O
with	O
their	O
teammates	O
to	O
destroy	O
their	O
opponents	O
 '	O
large	O
structure	O
called	O
an	O
Ancient	O
,	O
while	O
defending	O
their	O
own	O
.	O
</s>
<s>
Unlike	O
the	O
original	O
mod	O
,	O
which	O
is	O
largely	O
derived	O
from	O
the	O
setting	O
of	O
the	O
Warcraft	B-Application
series	O
,	O
the	O
standalone	O
games	O
share	O
their	O
own	O
continuity	O
.	O
</s>
<s>
Likewise	O
,	O
the	O
standalone	O
games	O
utilize	O
the	O
Source	B-Application
game	I-Application
engine	I-Application
and	O
Steam	B-Application
distribution	O
platform	O
-	O
both	O
developed	O
by	O
Valve	O
.	O
</s>
<s>
The	O
installment	O
which	O
established	O
the	O
Dota	B-Operating_System
intellectual	O
property	O
was	O
the	O
Warcraft	B-Application
III	I-Application
:	I-Application
Reign	I-Application
of	I-Application
Chaos	I-Application
custom	O
mod	O
Defense	B-Operating_System
of	I-Operating_System
the	I-Operating_System
Ancients	I-Operating_System
(	O
DotA	B-Operating_System
)	O
.	O
</s>
<s>
Independently	O
developed	O
and	O
released	O
by	O
the	O
pseudonymous	O
designer	O
Eul	O
in	O
2003	O
,	O
it	O
was	O
inspired	O
by	O
Aeon	O
of	O
Strife	O
,	O
a	O
multiplayer	O
StarCraft	B-Application
map	O
.	O
</s>
<s>
Before	O
every	O
DotA	B-Operating_System
match	O
,	O
up	O
to	O
ten	O
players	O
are	O
organized	O
into	O
two	O
teams	O
called	O
the	O
Scourge	O
and	O
the	O
Sentinel	O
-	O
inspired	O
by	O
the	O
factions	O
from	O
Warcraft	B-Application
lore	O
-	O
with	O
the	O
former	O
in	O
the	O
northeast	O
corner	O
and	O
the	O
latter	O
in	O
the	O
southwest	O
corner	O
of	O
a	O
nearly-symmetrical	O
map	O
.	O
</s>
<s>
At	O
the	O
center	O
of	O
each	O
base	O
is	O
a	O
central	O
structure	O
called	O
an	O
"	O
Ancient	O
"	O
,	O
which	O
is	O
either	O
the	O
World	O
Tree	O
for	O
the	O
Sentinel	O
or	O
the	B-Application
Frozen	I-Application
Throne	I-Application
for	O
the	O
Scourge	O
.	O
</s>
<s>
Valve	O
's	O
interest	O
in	O
the	O
Dota	B-Operating_System
intellectual	O
property	O
began	O
when	O
several	O
veteran	O
employees	O
,	O
including	O
Team	B-Application
Fortress	I-Application
2	I-Application
designer	O
Robin	O
Walker	O
and	O
executive	O
Erik	O
Johnson	O
,	O
became	O
fans	O
of	O
the	O
mod	O
and	O
wanted	O
to	O
build	O
a	O
modern	O
sequel	O
.	O
</s>
<s>
IceFrog	O
first	O
announced	O
his	O
new	O
position	O
through	O
his	O
blog	O
in	O
October	O
2009	O
,	O
with	O
Dota	B-Application
2	I-Application
being	O
officially	O
announced	O
a	O
year	O
later	O
.	O
</s>
<s>
Shortly	O
after	O
,	O
Valve	O
filed	O
a	O
trademark	O
claim	O
to	O
the	O
Dota	B-Operating_System
name	O
.	O
</s>
<s>
Holding	O
the	O
Dota	B-Operating_System
name	O
to	O
be	O
a	O
community	O
asset	O
,	O
Feak	O
and	O
Mescon	O
filed	O
an	O
opposing	O
trademark	O
for	O
Dota	B-Operating_System
on	O
behalf	O
of	O
DotA-Allstars	O
,	O
LLC	O
(	O
then	O
a	O
subsidiary	O
of	O
Riot	O
Games	O
)	O
in	O
August	O
2010	O
.	O
</s>
<s>
Rob	O
Pardo	O
,	O
the	O
executive	O
vice	O
president	O
of	O
Blizzard	O
Entertainment	O
at	O
the	O
time	O
,	O
similarly	O
stated	O
that	O
the	O
Dota	B-Operating_System
name	O
belonged	O
to	O
the	O
mod	O
's	O
community	O
.	O
</s>
<s>
Blizzard	O
acquired	O
DotA-Allstars	O
,	O
LLC	O
from	O
Riot	O
Games	O
and	O
filed	O
an	O
opposition	O
against	O
Valve	O
in	O
November	O
2011	O
,	O
citing	O
Blizzard	O
's	O
ownership	O
of	O
both	O
the	O
Warcraft	B-Application
III	I-Application
World	O
Editor	O
and	O
DotA-Allstars	O
,	O
LLC	O
as	O
proper	O
claims	O
to	O
the	O
franchise	O
name	O
.	O
</s>
<s>
The	O
dispute	O
was	O
settled	O
in	O
May	O
2012	O
,	O
with	O
Valve	O
retaining	O
commercial	O
rights	O
to	O
the	O
Dota	B-Operating_System
trademark	O
,	O
while	O
allowing	O
non-commercial	O
use	O
of	O
the	O
name	O
by	O
third-parties	O
.	O
</s>
<s>
An	O
early	O
goal	O
of	O
the	O
Dota	B-Application
2	I-Application
team	O
was	O
the	O
adaptation	O
of	O
Defense	B-Operating_System
of	I-Operating_System
the	I-Operating_System
Ancients	I-Operating_System
aesthetic	O
style	O
for	O
the	O
Source	B-Application
engine	I-Application
.	O
</s>
<s>
In	O
the	O
first	O
Q&A	O
session	O
regarding	O
Dota	B-Application
2	I-Application
,	O
IceFrog	O
explained	O
that	O
the	O
game	O
would	O
build	O
upon	O
the	O
mod	O
without	O
making	O
significant	O
changes	O
to	O
its	O
core	O
.	O
</s>
<s>
Valve	O
contracted	O
major	O
contributors	O
from	O
the	O
Defense	B-Operating_System
of	I-Operating_System
the	I-Operating_System
Ancients	I-Operating_System
community	O
,	O
including	O
Eul	O
and	O
artist	O
Kendrick	O
Lim	O
,	O
to	O
assist	O
with	O
the	O
sequel	O
.	O
</s>
<s>
Following	O
nearly	O
two	O
years	O
of	O
beta	O
testing	O
,	O
Dota	B-Application
2	I-Application
was	O
officially	O
released	O
on	O
Steam	B-Application
for	O
Windows	O
on	O
July	O
9	O
,	O
2013	O
,	O
and	O
for	O
OS	B-Operating_System
X	I-Operating_System
and	O
Linux	B-Application
on	O
July	O
18	O
,	O
2013	O
.	O
</s>
<s>
The	O
game	O
did	O
not	O
launch	O
with	O
every	O
hero	O
from	O
Defense	B-Operating_System
of	I-Operating_System
the	I-Operating_System
Ancients	I-Operating_System
.	O
</s>
<s>
Instead	O
,	O
the	O
missing	O
ones	O
were	O
added	O
in	O
various	O
post-release	O
updates	O
,	O
with	O
the	O
final	O
one	O
,	O
as	O
well	O
as	O
the	O
first	O
Dota	B-Application
2	I-Application
original	O
hero	O
,	O
being	O
added	O
in	O
2016	O
.	O
</s>
<s>
Since	O
its	O
release	O
,	O
Dota	B-Application
2	I-Application
has	O
been	O
cited	O
as	O
one	O
of	O
the	O
greatest	O
video	O
games	O
of	O
all	O
time	O
.	O
</s>
<s>
Artifact	B-Application
is	O
a	O
digital	B-Application
collectible	I-Application
card	I-Application
game	I-Application
based	O
on	O
Dota	B-Application
2	I-Application
,	O
developed	O
and	O
published	O
by	O
Valve	O
.	O
</s>
<s>
The	O
game	O
focuses	O
on	O
online	B-Application
player	O
versus	O
player	O
battles	O
across	O
three	O
boards	O
called	O
lanes	O
.	O
</s>
<s>
Development	O
of	O
it	O
began	O
in	O
late	O
2014	O
,	O
with	O
lead	O
designer	O
Richard	O
Garfield	O
being	O
brought	O
in	O
to	O
help	O
make	O
a	O
digital	B-Application
card	I-Application
game	I-Application
due	O
to	O
his	O
experience	O
with	O
creating	O
the	O
Magic	B-Application
:	I-Application
The	I-Application
Gathering	I-Application
franchise	O
.	O
</s>
<s>
Artifact	B-Application
was	O
released	O
for	O
Windows	O
,	O
macOS	B-Application
,	O
and	O
Linux	B-Application
in	O
November	O
2018	O
,	O
with	O
versions	O
planned	O
for	O
Android	B-Application
and	O
iOS	B-Application
.	O
</s>
<s>
While	O
its	O
gameplay	O
and	O
drafting	O
mechanics	O
received	O
praise	O
,	O
it	O
was	O
criticized	O
for	O
its	O
high	O
learning	B-General_Concept
curve	I-General_Concept
and	O
monetization	O
model	O
,	O
which	O
some	O
likened	O
to	O
being	O
pay-to-win	O
.	O
</s>
<s>
Dota	B-Application
Underlords	I-Application
is	O
a	O
free-to-play	O
auto	O
battler	O
,	O
a	O
type	O
of	O
chess-like	O
competitive	O
multiplayer	O
strategy	B-Application
video	I-Application
game	I-Application
,	O
developed	O
and	O
published	O
by	O
Valve	O
.	O
</s>
<s>
The	O
game	O
is	O
based	O
on	O
a	O
Dota	B-Application
2	I-Application
community-created	O
game	O
mode	O
called	O
Dota	B-Operating_System
Auto	I-Operating_System
Chess	I-Operating_System
,	O
with	O
journalists	O
noting	O
the	O
parallel	O
modding	O
origins	O
that	O
DotA	B-Operating_System
had	O
from	O
Warcraft	B-Application
III	I-Application
.	O
</s>
<s>
It	O
was	O
released	O
in	O
early	O
access	O
in	O
June	O
2019	O
for	O
Android	B-Application
,	O
iOS	B-Application
,	O
macOS	B-Application
,	O
Windows	O
,	O
and	O
Linux	B-Application
,	O
with	O
it	O
planned	O
to	O
be	O
officially	O
released	O
in	O
February	O
2020	O
.	O
</s>
<s>
One	O
of	O
the	O
many	O
auto	O
battler	O
games	O
that	O
released	O
following	O
the	O
popularity	O
of	O
Dota	B-Operating_System
Auto	I-Operating_System
Chess	I-Operating_System
,	O
critics	O
considered	O
it	O
one	O
of	O
the	O
easiest	O
to	O
get	O
into	O
for	O
newer	O
players	O
of	O
the	O
genre	O
.	O
</s>
<s>
In	O
Dota	B-Application
Underlords	I-Application
,	O
where	O
players	O
place	O
characters	O
,	O
known	O
as	O
heroes	O
,	O
on	O
an	O
8x8	O
grid-shaped	O
battlefield	O
.	O
</s>
<s>
A	O
match	O
features	O
up	O
to	O
eight	O
players	O
online	B-Application
who	O
take	O
turns	O
playing	O
against	O
each	O
other	O
in	O
a	O
one-on-one	O
format	O
,	O
with	O
the	O
winner	O
being	O
the	O
final	O
player	O
standing	O
after	O
eliminating	O
all	O
of	O
the	O
opposing	O
players	O
.	O
</s>
<s>
An	O
anime	O
television	O
series	O
based	O
on	O
the	O
franchise	O
,	O
Dota	B-Operating_System
:	O
Dragon	B-Operating_System
's	I-Operating_System
Blood	I-Operating_System
,	O
premiered	O
on	O
Netflix	O
in	O
March	O
2021	O
.	O
</s>
<s>
Swedish	O
electronic	O
music	O
artist	O
Basshunter	O
released	O
"	O
Vi	O
sitter	O
i	O
Ventrilo	B-Operating_System
och	O
spelar	O
DotA	B-Operating_System
"	O
in	O
2006	O
.	O
</s>
<s>
The	O
lyrics	O
,	O
in	O
Swedish	O
,	O
are	O
about	O
using	O
the	O
voice	B-Protocol
chat	I-Protocol
program	O
Ventrilo	B-Operating_System
while	O
playing	O
Defense	B-Operating_System
of	I-Operating_System
the	I-Operating_System
Ancients	I-Operating_System
.	O
</s>
<s>
IceFrog	O
(	O
born	O
)	O
is	O
the	O
pseudonymous	O
lead	O
designer	O
of	O
Defense	B-Operating_System
of	I-Operating_System
the	I-Operating_System
Ancients	I-Operating_System
and	O
Dota	B-Application
2	I-Application
.	O
</s>
<s>
His	O
involvement	O
with	O
the	O
series	O
began	O
in	O
2005	O
,	O
when	O
he	O
inherited	O
the	O
reins	O
of	O
DotA	B-Operating_System
Allstars	I-Operating_System
from	O
"	O
Neichus	O
"	O
,	O
who	O
himself	O
inherited	O
it	O
from	O
Steve	O
"	O
Guinsoo	B-Operating_System
"	O
Feak	O
.	O
</s>
<s>
In	O
2010	O
,	O
an	O
anonymous	O
person	O
who	O
claimed	O
to	O
be	O
a	O
Valve	O
employee	O
wrote	O
a	O
blog	O
post	O
titled	O
"	O
The	O
Truth	O
About	O
IceFrog	O
"	O
,	O
in	O
which	O
he	O
claims	O
that	O
IceFrog	O
had	O
previously	O
worked	O
secretly	O
on	O
Heroes	B-Application
of	I-Application
Newerth	I-Application
for	O
S2	O
Games	O
before	O
joining	O
Valve	O
in	O
2009	O
,	O
as	O
well	O
as	O
stating	O
his	O
identity	O
as	O
Abdul	O
Ismail	O
.	O
</s>
<s>
A	O
court	O
document	O
regarding	O
the	O
ownership	O
of	O
the	O
Dota	B-Operating_System
intellectual	O
property	O
from	O
April	O
2017	O
confirmed	O
Ismail	O
as	O
the	O
identity	O
of	O
IceFrog	O
,	O
as	O
well	O
as	O
his	O
pre-Valve	O
contributions	O
in	O
Heroes	B-Application
of	I-Application
Newerth	I-Application
.	O
</s>
