vms-empire.6

.\" $Id: empire.6,v 1.3 2000/07/28 05:12:50 esr Exp $  - (c) Copyright 1987, 1988 Chuck Simmons */
.\"
.\"   Copyright (C) 1987, 1988 Chuck Simmons
.\"
.\" See the file COPYING, distributed with empire, for restriction
.\" and warranty information.
.\"
.TH Empire 6
.SH NAME
empire -- the wargame of the century
.SH SYNOPSIS
empire [-w water] [-s smooth] [-d delay]
.SH DESCRIPTION
Empire is a simulation of a full-scale war between two
emperors, the computer and you.  Naturally, there is only
room for one, so the object of the game is to destroy
the other.  The computer plays by the same rules that you
do.
.TP 10
.BI \-w water\^
This option controls the amount of water on the map.
This is given as the percentage of the map which should
be water.  The default is 70% water.  \f2water\fP
must be an integer in the between 10 and 90 inclusive.
.TP
.BI \-s smooth\^
This controls the smoothness of the map.  A low value
will produce a highly chaotic map with lots of small
islands or lakes.  A high value will produce a map
with a few scattered continents.  Be forewarned that
a high value will cause the program to take a long
time to start up.  The default value is 5.
.TP
.BI \-d delay\^
This option controls the length of time the computer will
delay after printing informational messages at the top of
the screen.  \f2delay\fP is specified in milliseconds.  The
default value is 2000 which allows the user two seconds to
read a message.
.SH EXAMPLES
empire -w90 -s2
.P
This produces a map with many islands.
.P
empire -w50 -s0
.P
This produces a really strange map.  These values
are not recommended for the faint at heart.
.P
empire -w10
.P
This produces a map with lots of land and a few lakes.
The computer will have a hard time on this sort of map
as it will try and produce lots of troop transports,
which are fairly useless.
.P
There is one other option.
.TP
.BI \-S interval\^
.P
sets the \fIsave interval\fR for the game (default is 10). Once per
\fIinterval\fR turns the game state will be automatically saved after
your move. It will be saved in any case when you change modes or
do various special things from command mode, such as `M' or `N'.
.SH INTRODUCTION
Empire is a war game played between you and the user.  The world
on which the game takes place is a square rectangle containing cities,
land, and water.  Cities are used to build armies, planes, and ships
which can move across the world destroying enemy pieces, exploring,
and capturing more cities.  The objective of the game is to destroy
all the enemy pieces, and capture all the cities.
.P
The world is a rectangle 60 by 100 squares on a side.  The world
consists of sea (.), land (+), uncontrolled
cities (*), computer-controlled cities (X), and cities that you
control (O).
.P
The world is displayed on the player's screen during
movement.  (On terminals with small screens, only a portion of
the world is shown at any one time.)
Each piece is represented by a unique
character on the map.  With a few exceptions, you can
only have one piece on a given location.  On the map, you
are shown only the 8 squares adjacent to your units.
This information is updated before and during each of your moves.
The map displays the most recent information known.
.P
The game starts by assigning you one city and the
computer one city.  Cities can produce new pieces.  Every
city that you own produces more pieces for you according
to the cost of the desired piece.  The typical play of the
game is to issue the Automove command until you decide
to do something special.  During movement in each round,
the player is prompted to move each piece that does not
otherwise have an assigned function.
.P
Map coordinates are 4-digit numbers.  The first two
digits are the row, the second two digits are the
column.
.SH PIECES
The pieces are as follows:
.P
.TS
center box tab(;);
l | c | c | r | r | r | c.
Piece;You;Enemy;Moves;Hits;Str;Cost
_
Army;A;a;1;1;1;5(6)
Fighter;F;f;8;1;1;10(12)
Patrol Boat;P;p;4;1;1;15(18)
Destroyer;D;d;2;3;1;20(24)
Submarine;S;s;2;2;3;20(24)
Troop Transport;T;t;2;1;1;30(36)
Aircraft Carrier;C;c;2;8;1;30(36)
Battleship;B;b;2;10;2;40(48)
Satellite;Z;z;10;--;--;50(60)
.TE
.P
The second column shows the map representation for your
units.
.P
The third shows the representations of enemy units.
.P
Moves is the number of squares that the unit can move in a
single round.
.P
Hits is the amount of damage a unit can take before it
is destroyed.
.P
Strength is the amount of damage a unit can inflict upon an
enemy during each round of an attack.
.P
Cost is the number of rounds needed for a city to produce
the piece.
.P
The number in parenthesis is the cost for a city to
produce the first unit.
.P
Each piece has certain advantages associated with it that
can make it useful.  One of the primary strategic aspects
of this game is deciding which pieces will be produced
and in what quantities.
.P
\f3Armies\f1 can only move on land, and are the only piece that can
move on land.  Only armies can capture cities.
This means that you must produce armies in order to win the
game.  Armies have a 50% chance of capturing a city when they
attack.  (Attacking one's own city results in the army's
destruction.  Armies that move onto the sea will drown.
Armies can attack objects at sea, but even if they win, they
will drown.)  Armies can be carried by troop transports.
If an army is moved onto a troop transport, then whenever
the transport is moved, the army will be moved with the
transport.  You cannot attack any piece at sea while on a
transport.
.P
\f3Fighters\f1 move over both land and sea, and they move 8 squares
per round.  Their high speed and great mobility make fighters
ideal for exploring.  However, fighters must periodically land
at user-owned cities for refueling.  A fighter can travel 32
squares without refeuling.  Fighters are also shot down if they
attempt to fly over a city which is not owned by the user.
.P
\f3Patrol boats\f1 are fast but lightly armored.  Therefore
they are useful for patrolling ocean waters and exploring.
In an attack against a stronger boat, however, patrol boats
will suffer heavy casulties.
.P
\f3Destroyers\f1 are fairly heavily armored and reasonably quick
to produce.  Thus they are useful for destroying enemy transports
which may be trying to spread the enemy across the face of the
world.
.P
When a \f3submarine\f1 scores a hit, 3 hits are exacted instead of 1.
Thus submarines can inflict heavy damage in a fight against
heavily armored boats.  Notice that healthy submarines will
typically defeat healthy destroyers two-thirds of the time.
However, a submarine will defeat a fighter about two-thirds
of the time, while a destroyer will defeat a fighter three-fourths
of the time.
.P
\f3Troop transports\f1 are the only pieces that can carry armies.
A maximum of six armies can be carried by a transport.
On any world containing a reasonable amount of water,
transports will be a critical resource in winning the game.
Notice that the weakness of transports implies they need
protection from stronger ships.
.P
\f3Aircraft carriers\f1 are the only ships that can
carry fighters.  Carriers carry a maximum of the number
of hits left of fighters.  Fighters are refueled when they
land on a carrier.
.P
\f3Battleships\f1 are similar to destroyers except that they are
much stronger.
.P
\f3Satellites\f1 are only useful for reconaissance.  They can not
be attacked.  They are launched in a random diagonal orbit, and
stay up for 50 turns.  They can see one square farther than other
objects.
.P
All ships can move only on sea.  Ships can also dock in a
user-owned city.  Docked ships have damage repaired at the
rate of 1 hit per turn.  Ships which have suffered a lot
of damage will move more slowly.
.P
Because of their ability
to be repaired, ships with lots of hits such as Carriers and
Battleships have an additional advantage.
After suffering minor damage while destroying enemy shipping,
these ships can sail back to port and be quickly repaired before
the enemy has time to replenish her destroyed shipping.
.P
The following table gives the probability that the piece listed
on the side will defeat the piece listed at the top in a battle.
(The table assumes that both pieces are undamaged.)
.P
.TS
center box tab(;);
l | c | c | c | c | c.
AFPT;D;S;C;B
_
AFPT;50.0%;12.5%;25.0%;00.391%;00.0977%
D;87.5%;50.0%;25.0%;05.47%;00.537%
S;75.0%;75.0%;50.0%;31.3%;06.25%
C;99.6%;94.5%;68.7%;50.0%;04.61%
B;99.9%;99.5%;93.8%;95.4%;50.0%
.TE
.P
Notice, however, that when a ship has been damaged, the odds of
being defeated can go up quite a bit.  For example, a healthy
submarine has a 25% chance of defeating a battleship that has
had one hit of damage done to it, and a healthy submarine has
a 50% chance of defeating a carrier which has suffered two hits
of damage.
.SH "MOVEMENT FUNCTIONS"
There are a variety of movement functions.  The movement functions
of pieces can be specified in user mode and edit mode.
Cities can have movement functions set for each type of piece.
When a movement function for a type of pieces is set for a city,
then every time that type of piece appears in the city, the piece
will acquire that movement function.  Be forewarned that moving
loaded transports or loaded carriers into a city can have undesirable
side effects.
.P
Normally, when a movement
function has been specified, the piece will continue moving according to
that function until one of the following happen:
.TP 5
.B *
An enemy piece or unowned city appears next to the piece.  In this case
the piece will be completely awoken, unless its movement function has
been set to a specific destination.
Armies on ships and pieces inside
cities will not be awoken if the enemy piece is gone by the time it is
their turn to move.
.TP
.B *
You explicitly awaken the piece.
.TP
.B *
The piece can no longer move in accordance with its programmed function.
In this case, the piece will awaken \f2temporarily\fP.  You will be asked
to move the piece at which time you may awaken it.
.TP
.B *
The piece is a fighter which has just enough fuel (plus a small reserve)
to get to the nearest city.
In this case,
the piece will awaken completely, unless its movement function has
been set to a specific destination, or its movement function has been
set to \f2land\fP.
.P
The rationale behind this complexity is that fighters must be awoken
completely before they are out of range of a city
to prevent one from accidentally forgetting to waken the
fighter and then watching it fly off to its doom.  However, it is presumed
that when a path is set for the fighter, the fighter is not in danger of
running out of fuel.
.P
Pieces do not completely awaken when their function has been set to a
destination because it is slightly time consuming to reset the destination,
but very simple (one keystroke) to wake the piece.
.P
The movement functions are:
.TP 10
.B Attack
This function applies only to armies.  When this function is set,
the army will move toward the nearest enemy city, unowned city, or
enemy army.  This is useful when fighting off an invading enemy or
taking over a new continent.  When an army is set to this mode,
it will also explore nearby territory.  This tends to make
the "grope" movement mode pretty useless.
.TP
.B Awake
When pieces are awake, you will be asked for the direction in which
the piece should move on each turn.
.TP
.B Fill
This function applies to carriers and transports.  When this function is
specified, these ships sleep until they have been filled with fighters or
armies respectively.
.TP
.B Grope
This function causes a piece to explore.  The piece heads toward the nearest
unseen square of the map on each of its moves.  Some attempt is made to 
explore in an optimal fashion.
.TP
.B Land
This function applies to fighters and causes the fighter to head toward
the nearest transport or carrier.
.TP
.B Random
This movement function causes a piece to move at random to an adjacent
empty square.
.TP
.B Sentry
This movement function puts a piece to sleep.
The function of a city cannot be set to 'sleep'.
.TP
.B Transport
This movement function only works on armies.  The army sleeps until
an unfull transport passes by, at which point the army wakes up and
boards the transport.
.TP
.B Upgrade
This movement function only works with ships.  The ship will move
to the nearest owned city and remain there until it is repaired.
.TP
.B <dir>
Pieces can be set to move in a specified direction.
.TP
.B <dest>
Pieces can be set to move toward a specified square.  In this movement
mode, pieces take a shortest path toward the destination.  Pieces moving
in accordance with this function prefer diagonal moves that explore
territory.  Because of this, the movement of the piece may be
non-intuitive.
.P
As examples of how to use these movement functions, typically
when I have a new city on a continent, I set the Army function of the
city to \f2attack\f1.  Whenever an army is produced, it merrily goes off
on its way exploring the continent and moving towards unowned cities
or enemy armies or cities.
.P
I frequently set the ship functions for cities that are far from the
front to automatically move ships towards the front.
.P
When I have armies on a continent, but there is nothing to explore
or attack, I move the army to the shore and use the \f2transport\f1
function to have that army hop aboard the first passing transport.
.SH COMMANDS
There are three command modes.  The first of these is "command mode".
In this mode, you give commands that affect the game as a whole.
In the second mode, "move mode", you give commands to move your
pieces.  The third mode is "edit mode", and in this mode you can
edit the functions of your pieces and examine various portions of
the map.
.P
All commands are one character long.  The full mnemonic names are
listed below as a memorization aid.
The mnemonics are somewhat contrived because there are so few
characters in the English language.  Too bad this program isn't
written in Japanese, neh?
.P
In all command modes, typing "H" will print out a screen of help
information, and typing <ctrl-L> will redraw the screen.
.P
.SH COMMAND MODE
In command mode, the computer will prompt you for your orders.
The following commands can be given at this time:
.TP 10
.B Automove
Enter automove mode.  This command begins a new round of movement.
You will remain in move mode after each of the computer's turns.
(In move mode, the "O" command will return you to command mode
after the computer finishes its next turn.
.TP
.B City
Give the computer a random unowned city.  This command is useful if you
find that the computer is getting too easy to beat.
.TP
.B Date
The current round is displayed.
.TP
.B Examine
Examine the enemy's map.  This command is only valid after the computer
has resigned.
.TP
.B File
Print a copy of the map to the specified file.
.TP
.B Give
This command gives the computer a free move.
.TP
.B J
Enter edit mode where you can examine and change the functions
associated with your pieces and cities.
.TP
.B Move
Enter move mode for a single round.
.TP
.B N
Give the computer the number of free moves you specify.
.TP
.B Print
Display a sector on the screen.
.TP
.B Quit
Quit the game.
.TP
.B Restore
Restore the game from empsave.dat.
.TP
.B Save
Save the game in empsave.dat.
.TP
.B Trace
This command toggles a flag.  When the flag is set,
after each move, either yours or the computer's,
a picture of the world is written out to the file
'empmovie.dat'.  \f3Watch out!  This command produces lots of
output.\f1
.TP
.B Watch
This command allows you to watch a saved movie.
The movie is displayed in a condensed version so that
it will fit on a single screen, so the output may be
a little confusing.  This command is only legal if the
computer resigns.  If you lose the game, you cannot replay
a movie to learn the secrets of how the computer beat you.
Nor can you replay a movie to find out the current positions
of the computer's pieces.  When replaying a movie, it is
recommended that you use the \f2-d\f1 option to set the delay
to around 2000 milliseconds or so.  Otherwise the screen will be
updated too quickly for you to really grasp what is going on.
.TP
.B Zoom
Display a condensed version of the map on the screen.  The user map is
divided into small rectangles.  Each rectangle is displayed as one square
on the screen.  If there is a city in a rectangle, then it
is displayed.  Otherwise enemy pieces are displayed, then user pieces,
then land, then water, and then unexplored territory.  When pieces are
displayed, ships are preferred to fighters and armies.
.SH MOVE MODE
In move mode, the cursor will appear on the screen at the position
of each piece that needs to be moved.  You can then give commands
to move the piece.  Directions to move are specified by the
following keys:
.P
.fp 5 TT
.ft 5
.nf
        QWE
        A D
        ZXC
.fi
.ft 1
.P
These keys move in the direction of the key from S.  The
characters are not echoed and only 1 character is
accepted, so there is no need for a <Return>.  Hit the <Space>
bar if you want the piece to stay put.
.P
Other commands are:
.TP 10
.B Build
Change the production of a city.
.TP
.B Fill
Set the function of a troop transport or aircraft carrier to
\f2fill\f1.
.TP
.B Grope
Set the function of a piece to \f2grope\f1.
.TP
.BI I dir
Set the direction for a piece to move.
.TP
.B J
Enter edit mode.
.TP
.B Kill
Wake up the piece.  If the piece is a transport or carrier,
pieces on board will not be awoken.
.TP
.B Land
Set a fighter's function to \f2land\f1.
.TP
.B Out
Cancel automove mode.  At the end of the round, you will
be placed in command mode.
.TP
.B Print
Redraw the screen.
.TP
.B Random
Set a piece's function to \f2random\f1.
.TP
.B Sentry
Set a piece's function to \f2sentry\f1.
.TP
.B Transport
Set an army's function to \f2transport\f1.
.TP
.B Upgrade
Set a ship's function to \f2upgrade\f1.
.TP
.BI V "piece func"
Set the city movement function for the specified piece
to the specified function.  For example, typing "VAY" would
set the city movement function for armies to \f2attack\f1.  Whenever
an army is produced in the city (or whenever a loaded transport
enters the city), the army's movement function
would be set to \f2attack\f1.
.TP
.B Y
Set an army's function to \f2attack\f1.
.TP
.B ?
Display information about the piece.  The
function, hits left, range, and number of items on board are
displayed.
.P
Attacking something is accomplished by  moving  onto  the
square of the unit you wish to attack.  Hits are traded
off at 50% probability of a hit landing on one or the
other units until one unit is totally destroyed.  There
is only 1 possible winner.
.P
You are "allowed" to do \f3fatal\f1 things like attack your
own cities or other pieces.  If you try to make a fatal
move, the computer will warn you and give you a chance to
change your mind.
.P
You cannot move onto the edge of the world.
.SH EDIT MODE
In edit mode, you can move around the world and examine pieces
or assign them new functions.
To move the cursor around, use the standard direction
keys.
Other commands are:
.TP 10
.B Build
Change the production of the city under the cursor.
The program will prompt for the new production, and you
should respond with the key corresponding to the letter of the piece
that you want produced.
.TP
.B Fill
Set a transport's or carrier's function to \f2fill\f1.
.TP
.B Grope
Set a piece's function to \f2grope\f1.
.TP
.BI I dir
Set the function of a piece (or city) to the specified direction.
.TP
.B Kill
Wake all pieces at the current location.  If the location is a city,
the fighter path will also be canceled.
.TP
.B Mark
Select the piece or city at the current location.  This command
is used with the "N" command.
.TP
.B N
Set the destination of the piece previously selected with the "M"
command to the current square.
.TP
.B Out
Exit edit mode.
.TP
.BI Print sector
Display a new sector of the map.  The map is divided into
ten sectors of size 20 by 70.  Sector zero is in the upper-left
corner of the map.  Sector four is in the lower-left corner of
the map.  Sector five is in the upper-right corner, and sector
nine is in the lower-right corner.
.TP
.B Random
Set a piece to move randomly.
.TP
.B Sentry
Put a piece to sleep.
.TP
.B Transport
Set an army's function to \f2transport\f1.
.TP
.B Upgrade
Set a ship's function to \f2upgrade\f1.
.TP
.BI V "piece func"
Set the city movement function for a piece.
.TP
.B Y
Set an army's function to \f2attack\f1.
.TP
.B ?
Display information about a piece or city.
For a city, the production, time of completion of
the next piece, movement functions, and the number of fighters and ships
in the city are displayed.
.P
Note that you cannot directly affect anything inside a city with
the editor.
.SH HINTS
After you have played this game for a while, you will probably
find that the computer is immensely easy to beat.  Here are some
ideas you can try that may make the game more interesting.
.TP 5
.B *
Give the computer one or more extra cities before starting the game.
.TP
.B *
Try playing the game with a low smoothness value (try using the
-s2 or even -s0 option).
.TP
.B *
When starting the game, the program will ask you what difficulty
level you want.  Here "difficulty level" is a misnomer.  To compute
a difficulty level, the program looks at each continent and counts
the number of cities on the continents.  A high "difficulty level"
gives the computer a large continent with many cities, while the
user gets a small continent with few cities.  A low "difficulty level"
has the opposite effect.  It may be the case that the computer will
play better when the "difficulty level" is low.  The reason for this
is that the computer is forced to move armies to multiple continents
early in the game.
.SH HISTORY
Apparently, this game was originally written outside of Digital,
probably at a university.  The game was ported to DEC's VAX/VMS
from the TOPS-10/20 FORTRAN sources available around fall 1979.
The original authors listed in my old documentation are
Mario DeNobili and Thomas N. Paulson.
Support for different terminal types was added by Craig Leres.
.P
Ed James got hold of the sources at Berkeley and converted
portions of the code to C, mostly to use curses for the screen
handling.  He published his modified sources on the net in
December 1986.  Because this game ran on VMS machines for so
long, a previous version is known as VMS Empire.
.P
In 1987 Chuck Simmons at Amdahl
reverse engineered the program and wrote a
version completely written in C.  In doing so, he completely
modified the computer strategy, the commands, the piece types,
many of the piece attributes, and the algorithm for creating maps.
.SH FILES
.TP 10
\f2empsave.dat\f1
holds a backup of the game.  Whenever empire is run,
it will reload any game in this file.
.TP
\f2empmovie.dat\f1
holds a history of the game so that the game can be replayed as
a "movie".
.SH BUGS
No doubt numerous.
.P
Satellites are not completely implemented.  You should be able to
move to a square that contains a satellite, but the program won't
let you.  Enemy satellites should not cause your pieces to awaken.
.SH AUTHORS
.nf
Original concept by Mario DeNobili and Thomas N. Paulson.
Support for different terminal types added by Craig Leres.
Curses support added by Ed James.
C/Unix version written by Chuck Simmons
Colorization by Eric S. Raymond.
Probability table corrected by Michael Self.
.fi
.SH COPYLEFT
.fn
Copyright (C) 1987, 1988 Chuck Simmons

See the file COPYING, distributed with empire, for restriction
and warranty information.
.fi