<s>
Cataclysm	B-Application
:	I-Application
Dark	I-Application
Days	I-Application
Ahead	I-Application
(	O
CDDA	O
)	O
is	O
an	O
open-source	B-Application
roguelike	O
video	O
game	O
.	O
</s>
<s>
Cataclysm	B-Application
:	I-Application
Dark	I-Application
Days	I-Application
Ahead	I-Application
is	O
a	O
fork	B-Application
of	O
the	O
original	O
game	O
Cataclysm	O
.	O
</s>
<s>
The	O
game	O
is	O
freely	B-License
downloadable	I-License
on	O
the	O
game	O
's	O
website	O
and	O
the	O
source	O
code	O
is	O
also	O
freely	O
available	O
on	O
the	O
project	O
's	O
GitHub	B-Application
repository	O
under	O
the	O
CC	O
BY-SA	O
Creative	O
Commons	O
license	O
.	O
</s>
<s>
Rock	O
,	O
Paper	O
,	O
Shotgun	O
named	O
CDDA	O
one	O
of	O
"	O
The	O
50	O
Best	O
Free	B-Application
Games	I-Application
on	O
PC	O
"	O
in	O
2016	O
.	O
</s>
<s>
The	O
game	O
is	O
text-based	O
,	O
though	O
alternative	O
graphical	O
tilesets	B-Application
are	O
available	O
.	O
</s>
<s>
This	O
includes	O
both	O
things	O
required	O
for	O
day-to-day	O
survival	O
such	O
as	O
scavenging	O
,	O
hunting	O
,	O
and	O
finding	O
shelter	O
,	O
as	O
well	O
as	O
larger	O
goals	O
such	O
as	O
farming	B-Application
,	O
installing	O
bionics	B-Application
,	O
making	O
and	O
repairing	O
vehicles	O
,	O
and	O
constructing	O
homes	O
.	O
</s>
<s>
XE-037	O
escaped	O
the	O
lab	O
environment	O
,	O
causing	O
an	O
enormous	O
zombie	B-Application
outbreak	I-Application
and	O
manipulating	O
the	O
population	O
through	O
people	O
's	O
moods	O
,	O
making	O
many	O
people	O
violent	O
.	O
</s>
<s>
Though	O
the	O
cataclysm	O
is	O
predominantly	O
a	O
zombie	B-Application
apocalypse	I-Application
,	O
many	O
other	O
disastrous	O
events	O
are	O
going	O
on	O
,	O
including	O
invasions	O
from	O
fungi	O
,	O
Triffids	O
,	O
Lovecraftian	O
monsters	O
such	O
as	O
Mi-Gos	O
that	O
have	O
built	O
encampments	O
and	O
towers	O
around	O
the	O
world	O
,	O
and	O
caves	O
containing	O
sewer	O
rats	O
and	O
a	O
rat	O
king	O
.	O
</s>
<s>
Prior	O
to	O
the	O
cataclysm	O
,	O
robots	B-Algorithm
were	O
becoming	O
widespread	O
in	O
various	O
workplaces	O
such	O
as	O
hospitals	O
,	O
police	O
stations	O
,	O
and	O
mines	O
.	O
</s>
<s>
Cataclysm	B-Application
:	I-Application
Dark	I-Application
Days	I-Application
Ahead	I-Application
is	O
based	O
on	O
the	O
earlier	O
game	O
Cataclysm	O
whose	O
source	O
code	O
was	O
made	O
open-source	B-Application
under	O
the	O
Creative	O
Commons	O
CC	O
BY-SA	O
license	O
on	O
GitHub	B-Application
by	O
the	O
original	O
author	O
Whales	O
in	O
October	O
2010	O
.	O
</s>
<s>
After	O
the	O
Cataclysm	O
author	O
ended	O
the	O
development	O
around	O
2012	O
,	O
the	O
game	O
's	O
community	O
forked	B-Application
the	O
game	O
into	O
a	O
new	O
repository	O
called	O
Cataclysm	B-Application
:	I-Application
Dark	I-Application
Days	I-Application
Ahead	I-Application
in	O
early	O
2013	O
.	O
</s>
<s>
The	O
game	O
is	O
made	O
with	O
ncurses	B-Language
to	O
provide	O
text	O
based	O
graphics	O
;	O
later	O
a	O
Simple	B-Operating_System
DirectMedia	I-Operating_System
Layer	I-Operating_System
(	O
SDL	O
)	O
version	O
with	O
graphical	O
tiles	O
became	O
available	O
.	O
</s>
<s>
However	O
,	O
the	O
stable	O
versions	O
are	O
considered	O
"	O
snapshots	O
"	O
of	O
development	O
rather	O
than	O
the	O
primary	O
version	O
,	O
with	O
the	O
daily	O
updated	O
experimental	O
branch	B-General_Concept
being	O
the	O
"	O
master	O
"	O
version	O
of	O
the	O
game	O
.	O
</s>
<s>
In	O
December	O
2015	O
,	O
an	O
unofficial	O
launcher	O
was	O
created	O
for	O
CDDA	O
under	O
an	O
open-source	B-Application
MIT	B-License
license	I-License
to	O
allow	O
players	O
to	O
stay	O
up	O
to	O
date	O
with	O
the	O
latest	O
releases	O
and	O
third-party	O
mods	O
.	O
</s>
<s>
The	O
game	O
also	O
manages	O
numerous	O
other	O
mechanics	O
about	O
the	O
player	O
including	O
drug	O
addiction	O
,	O
mutations	O
,	O
broken	O
limbs	O
,	O
and	O
bionic	B-Application
implants	I-Application
.	O
</s>
<s>
Traits	O
that	O
have	O
a	O
greater	O
impact	O
on	O
gameplay	O
have	O
more	O
points	O
associated	O
with	O
them	O
,	O
ranging	O
from	O
minor	O
traits	O
like	O
"	O
Tough	O
Feet	O
"	O
and	O
"	O
Clumsy	O
"	O
to	O
game-changing	O
traits	O
like	O
"	O
Night	O
Vision	O
"	O
or	O
"	O
Kaluptic	O
Psychosis	O
"	O
,	O
which	O
causes	O
hallucinations	B-General_Concept
,	O
and	O
even	O
"	O
Nyctophobia	O
"	O
,	O
which	O
hinders	O
the	O
ability	O
to	O
enter	O
dark	O
areas	O
and	O
causes	O
bad	O
effects	O
if	O
caught	O
out	O
in	O
darkness	O
.	O
</s>
<s>
The	O
farming	B-Application
season	O
usually	O
extends	O
from	O
late	O
spring	O
to	O
early	O
autumn	O
and	O
depends	O
on	O
external	O
temperature	O
.	O
</s>
<s>
The	O
wilderness	O
contains	O
many	O
animals	O
,	O
ranging	O
from	O
small	O
passive	O
animals	O
such	O
as	O
squirrels	O
,	O
rabbits	O
,	O
and	O
rats	O
,	O
to	O
large	O
aggressive	O
predators	O
and	O
sometimes	O
hostile	O
herbivores	O
ranging	O
from	O
moose	B-Language
to	O
wolves	O
and	O
bears	O
.	O
</s>
<s>
The	O
main	O
threats	O
to	O
the	O
characters	O
are	O
the	O
zombies	B-Application
that	O
roam	O
mainly	O
the	O
cities	O
and	O
some	O
areas	O
within	O
the	O
wilderness	O
.	O
</s>
<s>
Zombies	B-Application
come	O
in	O
many	O
shapes	O
,	O
abilities	O
and	O
sizes	O
,	O
and	O
most	O
(	O
but	O
not	O
all	O
of	O
them	O
)	O
are	O
infamous	O
for	O
their	O
ability	O
to	O
revive	O
for	O
some	O
time	O
if	O
they	O
are	O
not	O
butchered	O
or	O
smashed	O
to	O
a	O
pulp	O
.	O
</s>
<s>
As	O
the	O
days	O
go	O
on	O
,	O
many	O
zombies	B-Application
and	O
creatures	O
will	O
mutate	O
into	O
more	O
powerful	O
forms	O
,	O
progressively	O
increasing	O
difficulty	O
.	O
</s>
<s>
Mundane	O
animals	O
may	O
be	O
replaced	O
with	O
zombie	B-Application
or	O
mutant	O
versions	O
,	O
further	O
reducing	O
access	O
to	O
edible	O
meat	O
while	O
making	O
the	O
world	O
more	O
hostile	O
.	O
</s>
<s>
Despite	O
the	O
increasing	O
deadliness	O
of	O
zombies	B-Application
and	O
monsters	O
,	O
unlike	O
most	O
other	O
games	O
,	O
the	O
number	O
of	O
zombies	B-Application
and	O
monsters	O
in	O
a	O
given	O
area	O
(	O
not	O
counting	O
the	O
overall	O
infinite	O
world	O
)	O
is	O
limited	O
,	O
when	O
the	O
zombies	B-Application
and	O
monsters	O
of	O
an	O
area	O
are	O
dead	O
and	O
rendered	O
unable	O
to	O
revive	O
,	O
they	O
will	O
no	O
longer	O
spawn	O
in	O
that	O
area	O
.	O
</s>
<s>
Rock	O
,	O
Paper	O
,	O
Shotgun	O
named	O
it	O
number	O
39	O
of	O
"	O
The	O
50	O
Best	O
Free	B-Application
Games	I-Application
on	O
PC	O
"	O
in	O
October	O
2016	O
.	O
</s>
