<s>
Heretic	B-Application
is	O
a	O
dark	O
fantasy	O
first-person	O
shooter	O
video	O
game	O
released	O
in	O
December	O
1994	O
.	O
</s>
<s>
Using	O
a	O
modified	O
version	O
of	O
the	O
Doom	B-Application
engine	I-Application
,	O
Heretic	B-Application
was	O
one	O
of	O
the	O
first	O
first-person	O
games	O
to	O
feature	O
inventory	O
manipulation	O
and	O
the	O
ability	O
to	O
look	O
up	O
and	O
down	O
.	O
</s>
<s>
An	O
indirect	O
sequel	O
,	O
Hexen	B-Application
:	I-Application
Beyond	I-Application
Heretic	I-Application
,	O
was	O
released	O
the	O
following	O
year	O
.	O
</s>
<s>
Heretic	B-Application
II	I-Application
was	O
released	O
in	O
1998	O
,	O
which	O
served	O
as	O
a	O
direct	O
sequel	O
continuing	O
the	O
story	O
.	O
</s>
<s>
Three	O
brothers	O
(	O
D'Sparil	B-Application
,	O
Korax	O
,	O
and	O
Eidolon	B-Application
)	O
,	O
known	O
as	O
the	O
Serpent	O
Riders	O
,	O
have	O
used	O
their	O
powerful	O
magic	O
to	O
possess	O
seven	O
kings	O
of	O
Parthoris	O
,	O
turning	O
them	O
into	O
mindless	O
puppets	O
and	O
corrupting	O
their	O
armies	O
.	O
</s>
<s>
The	O
Serpent	O
Riders	O
thus	O
declared	O
the	O
Sidhe	O
as	O
heretics	B-Application
and	O
waged	O
war	O
against	O
them	O
.	O
</s>
<s>
While	O
the	O
Sidhe	O
retreat	O
,	O
one	O
elf	O
(	O
revealed	O
to	O
be	O
named	O
Corvus	O
in	O
Heretic	B-Application
II	I-Application
)	O
sets	O
off	O
on	O
a	O
quest	O
of	O
vengeance	O
against	O
the	O
weakest	O
of	O
the	O
three	O
Serpent	O
Riders	O
,	O
D'Sparil	B-Application
.	O
</s>
<s>
He	O
travels	O
through	O
the	O
"	O
City	O
of	O
the	O
Damned	O
"	O
,	O
the	O
ruined	O
capital	O
of	O
the	O
Sidhe	O
(	O
its	O
real	O
name	O
is	O
revealed	O
to	O
be	O
Silverspring	O
in	O
Heretic	B-Application
II	I-Application
)	O
,	O
then	O
past	O
the	O
demonic	O
breeding	O
grounds	O
of	O
Hell	O
's	O
Maw	O
and	O
finally	O
the	O
secret	O
Dome	O
of	O
D'Sparil	B-Application
.	O
</s>
<s>
After	O
defeating	O
them	O
,	O
the	O
player	O
must	O
seal	O
the	O
portal	O
and	O
so	O
prevent	O
further	O
infestation	O
,	O
but	O
after	O
he	O
enters	O
the	O
portal	O
guarded	O
by	O
the	O
Maulotaurs	O
,	O
he	O
finds	O
himself	O
inside	O
Sparil	O
's	O
dome	O
.	O
</s>
<s>
After	O
killing	O
D'Sparil	B-Application
,	O
Corvus	O
ends	O
up	O
on	O
a	O
perilous	O
journey	O
with	O
little	O
hope	O
of	O
returning	O
home	O
.	O
</s>
<s>
The	O
gameplay	O
of	O
Heretic	B-Application
is	O
heavily	O
derived	O
from	O
Doom	B-Application
,	O
with	O
a	O
level-based	O
structure	O
and	O
an	O
emphasis	O
on	O
finding	O
the	O
proper	O
keys	O
to	O
progress	O
.	O
</s>
<s>
Many	O
weapons	O
are	O
similar	O
to	O
those	O
from	O
Doom	B-Application
;	O
the	O
early	O
weapons	O
in	O
particular	O
are	O
near-exact	O
copies	O
in	O
functionality	O
to	O
those	O
seen	O
in	O
Doom	B-Application
.	O
</s>
<s>
Raven	O
added	O
a	O
number	O
of	O
features	O
to	O
Heretic	B-Application
that	O
differentiated	O
it	O
from	O
Doom	B-Application
,	O
notably	O
interactive	O
environments	O
,	O
such	O
as	O
rushing	O
water	O
that	O
pushes	O
the	O
player	O
along	O
,	O
and	O
inventory	O
items	O
.	O
</s>
<s>
In	O
Heretic	B-Application
,	O
the	O
player	O
can	O
pick	O
up	O
many	O
different	O
items	O
to	O
use	O
at	O
their	O
discretion	O
.	O
</s>
<s>
Heretic	B-Application
also	O
features	O
an	O
improved	O
version	O
of	O
the	O
Doom	B-Application
engine	I-Application
,	O
sporting	O
the	O
ability	O
to	O
look	O
up	O
and	O
down	O
within	O
constraints	O
,	O
as	O
well	O
as	O
fly	O
.	O
</s>
<s>
As	O
with	O
Doom	B-Application
,	O
Heretic	B-Application
contains	O
various	O
cheat	O
codes	O
that	O
allow	O
the	O
player	O
to	O
be	O
invulnerable	O
,	O
obtain	O
every	O
weapon	O
,	O
be	O
able	O
to	O
instantly	O
kill	O
every	O
monster	O
in	O
a	O
particular	O
level	O
,	O
and	O
several	O
other	O
abilities	O
.	O
</s>
<s>
If	O
the	O
player	O
uses	O
the	O
"	O
all	O
weapons	O
and	O
keys	O
"	O
cheat	O
(	O
"	O
IDKFA	B-Application
"	O
)	O
from	O
Doom	B-Application
,	O
a	O
message	O
appears	O
warning	O
the	O
player	O
against	O
cheating	O
and	O
takes	O
away	O
all	O
of	O
his	O
weapons	O
,	O
leaving	O
him	O
with	O
only	O
a	O
quarterstaff	O
.	O
</s>
<s>
If	O
the	O
player	O
uses	O
the	O
"	O
god	O
mode	O
"	O
cheat	O
(	O
"	O
IDDQD	B-Application
"	O
)	O
from	O
Doom	B-Application
,	O
the	O
game	O
will	O
display	O
a	O
message	O
saying	O
"	O
Trying	O
to	O
cheat	O
,	O
eh	O
?	O
</s>
<s>
The	O
original	O
shareware	B-License
release	O
of	O
Heretic	B-Application
came	O
bundled	O
with	O
support	O
for	O
online	O
multiplayer	O
through	O
the	O
new	O
DWANGO	O
service	O
.	O
</s>
<s>
Heretic	B-Application
was	O
developed	O
by	O
Raven	O
Software	O
with	O
assistance	O
by	O
publisher	O
id	O
Software	O
,	O
the	O
latter	O
of	O
which	O
had	O
recently	O
pioneered	O
the	O
first-person	O
shooter	O
genre	O
with	O
Wolfenstein	B-Application
3D	I-Application
and	O
Doom	B-Application
.	O
</s>
<s>
Brian	O
Raffel	O
,	O
the	O
game	O
's	O
director	O
and	O
vice-president	O
of	O
Raven	O
at	O
the	O
time	O
,	O
revealed	O
that	O
the	O
developer	B-Application
first	O
came	O
to	O
id	O
's	O
attention	O
with	O
the	O
release	O
of	O
its	O
debut	O
title	O
Black	B-Application
Crypt	I-Application
.	O
</s>
<s>
After	O
providing	O
Raven	O
with	O
a	O
modified	O
Wolfenstein	B-Application
3D	I-Application
engine	O
for	O
its	O
next	O
project	O
ShadowCaster	B-Application
and	O
being	O
impressed	O
by	O
the	O
final	O
result	O
,	O
id	O
requested	O
that	O
Raven	O
develop	O
a	O
medieval-themed/dark	O
fantasy	O
game	O
using	O
a	O
modified	O
version	O
of	O
id	O
's	O
signature	O
Doom	B-Application
engine	I-Application
.	O
</s>
<s>
They	O
then	O
took	O
instruction	O
from	O
id	O
programmer	B-Application
John	O
Carmack	O
to	O
simply	O
"	O
do	O
it	O
like	O
Doom	B-Application
,	O
and	O
add	O
the	O
fantasy	O
flavor.	O
"	O
</s>
<s>
Heretic	B-Application
began	O
development	O
in	O
March	O
1994	O
with	O
Ben	O
Gokey	O
as	O
lead	O
programmer	B-Application
and	O
a	O
rough	O
storyline	O
penned	O
by	O
Michael	O
Raymond-Judy	O
that	O
was	O
finalized	O
by	O
the	O
game	O
's	O
publisher	O
.	O
</s>
<s>
Assistant	O
programmer	B-Application
Chris	O
Rhinehart	O
was	O
responsible	O
for	O
adding	O
the	O
flight	O
mechanic	O
,	O
which	O
Raffel	O
described	O
as	O
a	O
"	O
happy	O
accident	O
"	O
.	O
</s>
<s>
The	O
original	O
version	O
of	O
Heretic	B-Application
was	O
only	O
available	O
through	O
shareware	B-License
registration	O
(	O
i.e.	O
</s>
<s>
The	O
retail	O
version	O
,	O
Heretic	B-Application
:	O
Shadow	O
of	O
the	O
Serpent	O
Riders	O
,	O
was	O
distributed	O
by	O
GT	O
Interactive	O
in	O
1996	O
,	O
and	O
featured	O
the	O
original	O
three	O
episodes	O
and	O
two	O
additional	O
episodes	O
:	O
The	O
Ossuary	O
,	O
which	O
takes	O
the	O
player	O
to	O
the	O
shattered	O
remains	O
of	O
a	O
world	O
conquered	O
by	O
the	O
Serpent	O
Riders	O
several	O
centuries	O
ago	O
,	O
and	O
The	O
Stagnant	O
Demesne	O
,	O
where	O
the	O
player	O
enters	O
Sparil	O
's	O
birthplace	O
.	O
</s>
<s>
This	O
version	O
was	O
the	O
first	O
official	O
release	O
of	O
Heretic	B-Application
in	O
Europe	O
.	O
</s>
<s>
A	O
free	O
patch	O
was	O
also	O
downloadable	O
from	O
Raven	O
's	O
website	O
to	O
update	O
the	O
original	O
Heretic	B-Application
with	O
the	O
content	O
found	O
in	O
Shadow	O
of	O
the	O
Serpent	O
Riders	O
.	O
</s>
<s>
On	O
January	O
11	O
,	O
1999	O
,	O
the	O
source	O
code	O
of	O
the	O
game	O
engine	O
used	O
in	O
Heretic	B-Application
was	O
published	O
by	O
Raven	O
Software	O
under	O
a	O
license	O
that	O
granted	O
rights	O
to	O
non-commercial	O
use	O
,	O
and	O
was	O
re-released	O
under	O
the	O
GNU	B-License
GPL-2.0-only	I-License
on	O
September	O
4	O
,	O
2008	O
.	O
</s>
<s>
This	O
resulted	O
in	O
ports	O
to	O
Linux	B-Application
,	O
Amiga	B-Device
,	O
Atari	B-Device
,	O
and	O
other	O
operating	O
systems	O
,	O
and	O
updates	O
to	O
the	O
game	O
engine	O
to	O
utilize	O
3D	O
acceleration	O
.	O
</s>
<s>
The	O
shareware	B-License
version	O
of	O
a	O
console	O
port	O
for	O
the	B-Operating_System
Dreamcast	I-Operating_System
was	O
also	O
released	O
.	O
</s>
<s>
Heretic	B-Application
and	O
Hexen	B-Application
shipped	O
a	O
combined	O
total	O
of	O
roughly	O
1	O
million	O
units	O
by	O
August	O
1997	O
.	O
</s>
<s>
Heretic	B-Application
received	O
generally	O
positive	O
reviews	O
,	O
garnering	O
78%	O
on	O
PC	O
Zone	O
.	O
</s>
<s>
While	O
remarking	O
that	O
Heretic	B-Application
is	O
a	O
thinly-veiled	O
clone	O
of	O
Doom	B-Application
,	O
and	O
that	O
its	O
being	O
released	O
in	O
Europe	O
after	O
its	B-Application
sequel	I-Application
and	O
with	O
Quake	B-Application
due	O
out	O
shortly	O
makes	O
it	O
somewhat	O
outdated	O
,	O
Maximum	O
nonetheless	O
regarded	O
it	O
as	O
an	O
extremely	O
polished	O
and	O
worthwhile	O
purchase	O
.	O
</s>
<s>
Heretic	B-Application
has	O
received	O
three	O
sequels	O
:	O
Hexen	B-Application
:	I-Application
Beyond	I-Application
Heretic	I-Application
,	O
Hexen	B-Application
II	I-Application
,	O
and	O
Heretic	B-Application
II	I-Application
.	O
</s>
<s>
The	O
game	O
was	O
re-released	O
for	O
Windows	O
on	O
Steam	B-Application
on	O
August	O
3	O
,	O
2007	O
.	O
</s>
<s>
Further	O
homages	O
to	O
the	O
series	O
have	O
been	O
made	O
in	O
other	O
id	O
Software	O
titles	O
;	O
In	O
2009	O
's	O
Wolfenstein	B-Application
,	O
which	O
Raven	O
Software	O
developed	O
,	O
Heretic'''s	O
Tomes	O
of	O
Power	O
are	O
collectible	O
power-ups	O
found	O
throughout	O
the	O
game	O
.	O
</s>
<s>
The	O
character	O
Galena	O
from	O
Quake	B-Application
Champions	I-Application
wears	O
armor	O
bearing	O
the	O
icon	O
of	O
the	O
Serpent	O
Riders	O
.	O
</s>
<s>
In	O
2014	O
,	O
Raven	O
co-founder	O
Brian	O
Raffel	O
had	O
expressed	O
interest	O
in	O
making	O
a	O
sequel	O
to	O
the	O
Heretic''	O
series	O
.	O
</s>
<s>
Rather	O
than	O
licensing	O
it	O
to	O
other	O
developers	B-Application
,	O
he	O
wants	O
Raven	O
to	O
do	O
it	O
themselves	O
.	O
</s>
