<s>
Kroz	B-Application
is	O
a	O
series	O
of	O
Roguelike	O
video	O
games	O
created	O
by	O
Scott	O
Miller	O
for	O
IBM	O
PC	O
compatibles	O
.	O
</s>
<s>
The	O
first	O
episode	O
in	O
the	O
series	O
,	O
Kingdom	B-Application
of	I-Application
Kroz	I-Application
,	O
was	O
released	O
in	O
1987	O
as	O
Apogee	O
Software	O
's	O
first	O
game	O
.	O
</s>
<s>
Kroz	B-Application
introduced	O
the	O
scheme	O
of	O
the	O
first	O
episode	O
being	O
free	O
and	O
charging	O
money	O
for	O
additional	O
episodes	O
;	O
a	O
technique	O
which	O
defined	O
the	O
business	O
model	O
for	O
Apogee	O
and	O
was	O
adopted	O
by	O
other	O
MS-DOS	B-Application
shareware	B-License
publishers	O
.	O
</s>
<s>
In	O
March	O
2009	O
,	O
the	O
whole	O
Kroz	B-Application
series	I-Application
was	O
released	O
as	O
freeware	B-License
by	O
Apogee	O
,	O
and	O
the	O
source	O
code	O
was	O
released	O
as	O
free	B-Application
software	I-Application
under	O
the	O
GPL-2.0-or-later	B-License
license	O
.	O
</s>
<s>
The	O
object	O
of	O
the	O
game	O
is	O
to	O
survive	O
numerous	O
levels	O
of	O
attacking	O
monsters	O
and	O
ultimately	O
find	O
the	O
priceless	O
Magical	O
Amulet	O
of	O
Kroz	B-Application
.	O
</s>
<s>
The	O
Kroz	B-Application
games	O
were	O
inspired	O
by	O
an	O
earlier	O
dungeon	O
crawling	O
game	O
,	O
Rogue	B-Application
.	O
</s>
<s>
Scott	O
Miller	O
tried	O
to	O
create	O
a	O
game	O
that	O
had	O
some	O
of	O
the	O
elements	O
of	O
Rogue	B-Application
,	O
but	O
with	O
less	O
randomness	O
and	O
more	O
reliance	O
on	O
the	O
abilities	O
of	O
the	O
player	O
than	O
on	O
luck	O
.	O
</s>
<s>
Miller	O
,	O
fond	O
of	O
including	O
backwards	O
words	O
in	O
his	O
games	O
,	O
came	O
up	O
with	O
the	O
name	O
by	O
spelling	O
Zork	B-Application
backwards	O
.	O
</s>
<s>
Kingdom	B-Application
of	I-Application
Kroz	I-Application
was	O
written	O
in	O
Turbo	B-Application
Pascal	I-Application
3.0	O
.	O
</s>
<s>
Later	O
games	O
in	O
the	O
series	O
were	O
written	O
in	O
Turbo	B-Application
Pascal	I-Application
5.0	O
.	O
</s>
<s>
The	O
game	O
was	O
implemented	O
entirely	O
in	O
the	O
80×25	O
16	O
color	O
CGA	B-Device
text	O
mode	O
of	O
IBM	O
PC	O
compatibles	O
,	O
using	O
various	O
characters	O
in	O
the	O
computer	O
's	O
character	B-General_Concept
set	I-General_Concept
,	O
as	O
well	O
as	O
different	O
colors	O
,	O
to	O
present	O
a	O
"	O
graphical	O
"	O
environment	O
.	O
</s>
<s>
The	O
game	O
uses	O
ASCII	B-Protocol
characters	I-Protocol
,	O
as	O
well	O
as	O
some	O
extended	B-Protocol
ASCII	I-Protocol
graphical	O
characters	O
from	O
the	O
original	O
IBM	O
PC	O
character	B-General_Concept
set	I-General_Concept
,	O
to	O
represent	O
the	O
player	O
character	O
,	O
walls	O
,	O
monsters	O
and	O
items	O
.	O
</s>
<s>
The	O
game	O
was	O
originally	O
distributed	O
as	O
shareware	B-License
.	O
</s>
<s>
It	O
was	O
later	O
expanded	O
to	O
consist	O
of	O
seven	O
episodes	O
,	O
with	O
only	O
the	O
first	O
episode	O
distributed	O
as	O
shareware	B-License
,	O
and	O
the	O
rest	O
available	O
commercially	O
.	O
</s>
<s>
Collection	O
Episode	O
Release	O
Levels	O
Notes	O
Original	O
Kroz	B-Application
Trilogy	O
#1	O
Kingdom	O
of	O
Kroz198725a.k.a.	O
</s>
<s>
Kingdom	B-Application
of	I-Application
Kroz	I-Application
II	O
#2	O
Caverns	O
of	O
Kroz198840a.k.a.	O
</s>
<s>
Caverns	O
of	O
Kroz	B-Application
II	O
#3	O
Dungeons	O
of	O
Kroz198930a.k.a.	O
</s>
<s>
Dungeons	O
of	O
Kroz	B-Application
II	O
Super	O
Kroz	B-Application
Trilogy	O
#4	O
Return	O
to	O
Kroz199020a.k.a.	O
</s>
<s>
Castle	O
of	O
Kroz	B-Application
#5	O
Temple	O
of	O
Kroz199020a.k.a.	O
</s>
<s>
Valley	O
of	O
Kroz	B-Application
#6	O
The	O
Final	O
Crusade	O
of	O
Kroz199025a.k.a.	O
</s>
<s>
The	O
first	O
two	O
games	O
in	O
the	O
series	O
,	O
Caverns	O
of	O
Kroz	B-Application
and	O
Dungeons	O
of	O
Kroz	B-Application
,	O
were	O
originally	O
published	O
in	O
the	O
disk	O
magazine	O
I.B.Magazette	O
in	O
1987	O
.	O
</s>
<s>
The	O
third	O
game	O
,	O
Kingdom	B-Application
of	I-Application
Kroz	I-Application
,	O
was	O
sent	O
in	O
1987	O
to	O
the	O
disk	O
magazine	O
Big	O
Blue	O
Disk	O
as	O
a	O
submission	O
for	O
a	O
contest	O
they	O
were	O
having	O
,	O
where	O
it	O
was	O
published	O
in	O
1988	O
.	O
</s>
<s>
At	O
the	O
same	O
time	O
,	O
Miller	O
,	O
looking	O
for	O
other	O
avenues	O
to	O
distribute	O
his	O
games	O
,	O
turned	O
to	O
the	O
shareware	B-License
model	O
.	O
</s>
<s>
Shareware	B-License
was	O
distributed	O
freely	O
through	O
bulletin	B-Application
board	I-Application
systems	I-Application
(	O
BBS	O
)	O
,	O
where	O
the	O
boards	O
 '	O
users	O
made	O
voluntary	O
donations	O
.	O
</s>
<s>
Since	O
shareware	B-License
was	O
not	O
very	O
profitable	O
at	O
the	O
time	O
,	O
Miller	O
developed	O
a	O
variation	O
of	O
the	O
shareware	B-License
model	O
,	O
dubbed	O
the	O
"	O
Apogee	O
model	O
"	O
,	O
in	O
which	O
only	O
a	O
fraction	O
of	O
the	O
game	O
would	O
be	O
made	O
available	O
to	O
play	O
for	O
free	O
on	O
BBS	O
.	O
</s>
<s>
He	O
applied	O
this	O
model	O
to	O
the	O
Kroz	B-Application
trilogy	O
by	O
sharing	O
only	O
Kingdom	B-Application
of	I-Application
Kroz	I-Application
over	O
BBS	O
while	O
retaining	O
the	O
other	O
two	O
for	O
sale	O
.	O
</s>
<s>
This	O
shareware	B-License
version	O
of	O
Kingdom	B-Application
of	I-Application
Kroz	I-Application
was	O
the	O
first	O
game	O
to	O
bear	O
the	O
name	O
of	O
Miller	O
's	O
one-man	O
company	O
,	O
Apogee	O
Software	O
Productions	O
.	O
</s>
<s>
Return	O
to	O
Kroz	B-Application
,	O
originally	O
called	O
Castle	O
of	O
Kroz	B-Application
,	O
was	O
initially	O
published	O
in	O
Big	O
Blue	O
Disk	O
in	O
1990	O
,	O
before	O
becoming	O
the	O
shareware	B-License
episode	O
of	O
the	O
second	O
trilogy	O
of	O
Kroz	B-Application
games	O
,	O
the	O
Super	O
Kroz	B-Application
Trilogy	O
.	O
</s>
<s>
In	O
1990	O
,	O
an	O
enhanced	O
version	O
of	O
Kingdom	B-Application
of	I-Application
Kroz	I-Application
was	O
released	O
as	O
Kingdom	B-Application
of	I-Application
Kroz	I-Application
II	O
,	O
which	O
became	O
the	O
shareware	B-License
episode	O
of	O
the	O
series	O
as	O
a	O
whole	O
.	O
</s>
<s>
Kingdom	B-Application
of	I-Application
Kroz	I-Application
II	O
was	O
different	O
from	O
the	O
original	O
version	O
,	O
and	O
incorporated	O
21	O
different	O
levels	O
,	O
many	O
of	O
them	O
from	O
later	O
games	O
in	O
the	O
series	O
,	O
especially	O
from	O
The	O
Lost	O
Adventures	O
of	O
Kroz	B-Application
.	O
</s>
<s>
The	O
original	O
Kingdom	B-Application
of	I-Application
Kroz	I-Application
I	O
stopped	O
being	O
distributed	O
as	O
shareware	B-License
,	O
but	O
was	O
still	O
available	O
commercially	O
,	O
and	O
was	O
then	O
marketed	O
as	O
the	O
third	O
episode	O
in	O
the	O
series	O
,	O
with	O
episodes	O
two	O
and	O
three	O
moving	O
up	O
one	O
place	O
.	O
</s>
<s>
For	O
a	O
time	O
,	O
the	O
series	O
consisted	O
of	O
seven	O
commercial	O
episodes	O
(	O
including	O
the	O
original	O
Kingdom	B-Application
of	I-Application
Kroz	I-Application
I	O
)	O
,	O
plus	O
an	O
enhanced	O
version	O
of	O
one	O
of	O
them	O
(	O
Kingdom	B-Application
of	I-Application
Kroz	I-Application
II	O
)	O
distributed	O
as	O
shareware	B-License
.	O
</s>
<s>
During	O
this	O
time	O
,	O
to	O
be	O
able	O
to	O
buy	O
the	O
commercial	O
episodes	O
,	O
the	O
shareware	B-License
episode	O
had	O
to	O
be	O
registered	O
first	O
.	O
</s>
<s>
In	O
1991	O
,	O
the	O
other	O
two	O
episodes	O
of	O
the	O
first	O
trilogy	O
were	O
enhanced	O
to	O
their	O
"	O
II	O
"	O
versions	O
,	O
and	O
the	O
original	O
Kingdom	B-Application
of	I-Application
Kroz	I-Application
I	O
stopped	O
being	O
available	O
,	O
being	O
replaced	O
by	O
its	O
enhanced	O
version	O
.	O
</s>
<s>
At	O
one	O
point	O
the	O
source	O
code	O
for	O
Kingdom	B-Application
of	I-Application
Kroz	I-Application
could	O
be	O
purchased	O
for	O
$190	O
,	O
Return	O
to	O
Kroz	B-Application
for	O
$350	O
and	O
The	O
Lost	O
Adventures	O
of	O
Kroz	B-Application
for	O
$950	O
.	O
</s>
<s>
Later	O
the	O
source	O
code	O
of	O
Kingdom	B-Application
of	I-Application
Kroz	I-Application
II	O
was	O
for	O
sale	O
for	O
$400	O
,	O
Return	O
to	O
Kroz	B-Application
for	O
$300	O
and	O
The	O
Lost	O
Adventures	O
of	O
Kroz	B-Application
for	O
$500	O
.	O
</s>
<s>
By	O
2009	O
,	O
the	O
source	O
code	O
was	O
released	O
under	O
the	O
GPL-2.0-or-later	B-License
license	O
.	O
</s>
<s>
The	O
original	O
Kingdom	B-Application
of	I-Application
Kroz	I-Application
game	O
took	O
top	O
honors	O
in	O
the	O
game	O
category	O
in	O
Big	O
Blue	O
Disk'''s	O
CodeQuest	O
'	O
87	O
programming	O
contest	O
in	O
1988	O
,	O
and	O
came	O
out	O
number	O
two	O
overall	O
.	O
</s>
<s>
The	O
Kroz	B-Application
concept	O
,	O
including	O
the	O
text	O
mode	O
implementation	O
,	O
was	O
cloned	O
by	O
Potomac	O
Computer	O
Systems	O
for	O
the	O
ZZT''	O
games	O
,	O
which	O
also	O
used	O
the	O
same	O
shareware	B-License
business	O
model	O
.	O
</s>
