<s>
Larn	B-Application
is	O
a	O
roguelike	O
computer	O
game	O
written	O
by	O
Noah	B-Application
Morgan	I-Application
in	O
1986	B-Application
for	O
the	O
UNIX	B-Application
operating	I-Application
system	I-Application
.	O
</s>
<s>
Morgan	O
's	O
original	O
version	O
of	O
Larn	B-Application
remains	O
part	O
of	O
the	O
NetBSD	B-Device
games	O
collection	O
.	O
</s>
<s>
Larn	B-Application
is	O
one	O
of	O
the	O
shorter	O
roguelike	O
games	O
.	O
</s>
<s>
It	O
can	O
take	O
many	O
hours	O
and	O
tens	O
(	O
or	O
even	O
hundreds	O
)	O
of	O
thousands	O
of	O
game	O
turns	O
to	O
beat	O
other	O
roguelikes	O
,	O
such	O
as	O
NetHack	B-Application
or	O
Ancient	B-Application
Domains	I-Application
of	I-Application
Mystery	I-Application
,	O
but	O
Larn	B-Application
can	O
reasonably	O
be	O
completed	O
in	O
one	O
play	O
session	O
.	O
</s>
<s>
Primary	O
development	O
of	O
Larn	B-Application
halted	O
in	O
1991	B-Application
with	O
version	O
12.3	O
,	O
but	O
its	O
open	B-Application
source	I-Application
nature	O
has	O
led	O
to	O
later	O
variants	O
.	O
</s>
<s>
Developers	O
have	O
ported	O
the	O
game	O
to	O
such	O
diverse	O
operating	B-General_Concept
systems	I-General_Concept
as	O
Solaris	B-Application
,	O
Amiga	B-Application
OS	I-Application
,	O
Atari	B-Application
TOS	I-Application
,	I-Application
and	O
Microsoft	B-Application
Windows	I-Application
.	O
</s>
<s>
On	O
October	O
4th	O
2015	O
,	O
a	O
GitHub	B-Application
repository	O
was	O
created	O
and	O
Larn	B-Application
started	O
to	O
be	O
developed	O
and	O
maintained	O
once	O
again	O
from	O
the	O
original	O
source	O
code	O
.	O
</s>
<s>
This	O
makes	O
Larn	B-Application
one	O
of	O
the	O
oldest	O
video	O
games	O
still	O
being	O
developed	O
.	O
</s>
<s>
In	O
1987	B-Application
,	O
Phil	O
Cordier	O
modified	O
the	O
Larn	B-Application
source	O
code	O
to	O
form	O
Ultra-Larn	O
,	O
or	O
more	O
commonly	O
,	O
ULarn	O
.	O
</s>
<s>
Larn	B-Application
is	O
one	O
of	O
the	O
first	O
roguelike	O
games	O
to	O
feature	O
a	O
persistent	O
home	O
levelin	O
this	O
case	O
,	O
a	O
town	O
.	O
</s>
<s>
The	O
goal	O
of	O
Larn	B-Application
is	O
for	O
the	O
player	O
to	O
traverse	O
a	O
dungeon	O
in	O
search	O
of	O
a	O
potion	O
that	O
will	O
cure	O
his	O
ailing	O
daughter	O
of	O
'	O
dianthroritis	O
 '	O
.	O
</s>
<s>
Larn	B-Application
increases	O
in	O
difficulty	O
each	O
time	O
it	O
is	O
finished	O
,	O
making	O
it	O
harder	O
for	O
players	O
to	O
perform	O
in-game	O
actions	O
,	O
such	O
as	O
destroying	O
walls	O
or	O
statues	O
.	O
</s>
<s>
Larn	B-Application
also	O
requires	O
the	O
player	O
pay	O
a	O
tax	O
in	O
subsequent	O
games	O
based	O
on	O
the	O
amount	O
of	O
money	O
in	O
the	O
player	O
's	O
possession	O
when	O
the	O
game	O
was	O
last	O
won	O
.	O
</s>
