╔══ SPACE EMPIRES IV ══╗ (f0283f8) [ RULES ]

Concept

A massively multiplayer turn-based war game, loosely modelled on the gameplay of the PBM game sold in the 80s as Space Empires.

Updated!

This version has a new fleet system, new treasures, new treasure effects, and a more interactive combat system.

The game is turn-based. Players submit orders for their units, the server processes those orders, and when processing is complete the game emails a text report for each player containing the results.

To run a game you should host the dockerfile and proxy port 8001. Details to follow.

Gameplay example

A player first gets a report of the current state of their empire, which traditionally starts as a single world with a ship factory.

TURN 1
W1<MING>(2,3,4,5) (ind=50 rms=13 rmp=10 pop=31)

... which means

  • a world named W1 connected to 4 other worlds (worlds W2, W3, W4 and W5)
  • owned by the empire of MING
  • has the industrial production capacity (ind) of 50 ships per turn
  • holds raw materials (rms) sufficient to build 13 ships
  • producing 10 more raw materials (rmp) every turn
  • with a population of 31 million

The player reads the report and perhaps submits the following orders:

B12 F1 W1
B1 F2 W1

...which means

  • Build 12 ships onto a new fleet named F1 at W world 1.
  • Build 1 ship onto a new fleet named F2 at W world 1.
  • Don't give an order to F2, but leave it at W1 to defend the world.

Major differences from classic 80s Space Empires

If you played the classic game, you might notice that there are now no fleets at the world on the first turn. In this game, players create fleets when required. A fleet containing zero ships is not possible. There are no "Home Fleets." To defend a world, create a normal fleet and give it no orders. The fleet will enter defense mode automatically and double its defence points. On the turn a fleet is created, the fleet cannot immediately move. Your first turn will be creating fleets for movement in turn 2.

In addition to fleet creation, there are some other minor changes to the classic rules such as:

  • the order of combat events
  • alternative ship combat strategies
  • optional supply chain automation

Game Rules

The Universe

Some facts about the Universe

The universe is of a set of worlds, connected via a galactic hyperspace network. Travel between worlds is only possible through the connections of this hyperspace network.

The game may consist of a grid of worlds, where each world is connected to four neighbors (which can be visualised as north, south, east, and west)

Or the game might be a completely organic mess of interconnections and one-way links.

The chosen universe generator will create the map before the game starts. It is up to the runner of the game to give players any information about the structure of the universe. It might be entirely secret, it might be fully published, or you might be told the general structure of the map, it's not covered here.

Worlds

Worlds have a number of attributes:

World Attribute Abbreviation Game effect
Industry IND Each point of Industry is capable of turning one unit of Raw Material into one Ship on one turn, as long as the Population is greater than zero.
Raw Materials Stored RMS One unit of Raw Material is enough to create one Ship
Raw Materials Produced RMP The number of units of Raw Materials produced by the world per turn
Population POP Millions of inhabitants. If this is zero, the world is unowned. Population does not increase during the game.
Owner Every world will have one owner, or unowned.
World number Every world will have a unique numerical identifier.

Ships

All ships in the game are identical. All ships are armed. Each ship may carry one unit of cargo. A ship carrying cargo is encumbered in battle.

Fleets

Every ship must belong to a fleet. A fleet contains one or more ships. A fleet is given a Strategy each turn. A fleet not given a strategy has the default strategy, which is to fire when ordered and defend when attacked. Ships in a fleet move and fight together as a unit.

Turns

Each turn has three phases.

  • Combat phase

    • Fleets are assigned strategies and targets.
    • Combat is resolved according to the combat rules.
    • Fleets with no ships after the combat phase are eliminated at the end of the Combat phase and will not participate in remaining phases.

  • Bombardment phase

    • If there are no enemy ships with DEFAULT or INTERDICTION strategy, then surviving fleets with bombardment orders (e.g. AF99P) destroy Industry or Population.

  • Resolution phase

    • Construct new fleets
    • Transfer ships between fleets
    • Load and unload cargo and treasures

  • Movement phase

    • Fleets move from one to three hyperspace jumps
    • Fleets which loaded or unloaded cargo and treasure may not move in the same turn
    • Ambushes occur in this phase

Reports

Each player will get a report of the status of their empire at the start of every turn. The report will be in the following format, but may also be delivered as a .dot file and/or a json file for processing by graphical clients.

Example reports

    W1<MING>(2,3,4,5) (ind=13 rms=22 rmp=10 pop=31)
        F2 <MING> 10, I
        F3 <BOSCO> 20/5, TGT=POP
        F5 <BOSCO> 20, <-W2
        F4 <MING> 5, X<BOSCO F-5>
        F9 <MING> 30, TGT=F-5
        F10 <BOSCO> -> W2

The world named W1 is

  • <MING> owned by the empire of Ming

  • (2,3,4,5) Ships can jump from here to worlds W2, W3, W4 and W5

  • ind=13 The world has 13 points of Industry. This means it can convert up to 13 units of raw materials into ships on each turn.

  • rms=22 the world has 22 points of Raw Materials Stored. This means that it can build 13 ships, and still have 9 points of Raw Materials remaining.

  • rmp=10 the world produced 10 points of Raw Materials Production every turn. This happens as the final act of the resolution phase, after construction is complete. To continue the example above, when the world has 9 points of Raw Materials remaining after building ships, at the start of the next turn the world will have 9+10=19 points of Raw Materials Stored.

  • pop=31 the world has a Population of between 30 and 31 million. A world with 0 Population cannot produce raw materials, and cannot build ships.

    F2 10, I

This is a fleet, named F2

  • <MING> It is also owned by the empire of Ming

  • 10 There are 10 ships in the fleet

  • ,I At the start of the last turn, this fleet was using the INTERDICTION strategy.

    F3 20/5, TGT=POP

This is an enemy fleet, which we have given the name F3. Fleet names of enemy fleets will never be the same as any of our own fleets.

Note that the fleet's name is not the same as the name the enemy player used. This is because we don't know the name that Bosco gave her fleet, so we refer to it as F3 because it is the name we gave it when we first saw it.

  • TGT=POP Last turn, this enemy fleet bombarded the population of the world where it is located.

  • 20/5 There are 20 ships on the fleet, and the fleet is carrying 5 units of Raw Materials.

    F5 20, <-W2

Bosco's fleet of 20 ships, which we have designated F5. It arrived from world W2 in the last turn.

F4 <MING> 5, X<BOSCO F-5>

F4 is a fleet we captured from Bosco last turn. X<BOSCO F-5> means we captured this ship from Bosco at the end of the combat phase in the last turn. It used to be designated F-5 but because it's ours we have given it a new name F4. Names for captured fleets are the lowest unused number available.

F9 <MING> 30, TGT=F5

F9 is a fleet which fired on F5 during the combat phase last turn.

F10 <BOSCO> -> W2

This is a marker to say that the Bosco's fleet F10 left for W2 at the end of the last turn. It is no longer here, you cannot perform any action on it. If we own world W2 or have ships at world W2 we will see a report showing the fleet's arrival.

Movement

Fleets may travel from one world to another with the M order.

If you know the links between them, you can move a ship up to three jumps from its origin in a single turn. For example the following order results in the ship arriving at W4 at the start of the next turn.

M2W2W3W4

Fleets

Ships move in groups called Fleets.

A Fleet acts as a single unit, moving and attacking as one. You may split or join fleets during the Resolution phase.

Movement restrictions

  • A fleet cannot move on the same turn as it participates in combat unless it only participates as a defender (See the table of fleet strategies for details).
  • A fleet which has just been created cannot move on the same turn as it was constructed.
  • A fleet involved in a transfer of ships, or which has loaded or unloaded cargo or treasure, cannot move on the same turn as the transfer.

Cargo

One ship may carry one unit of Raw Materials. A Fleet containing even a single ship carrying cargo will be at a disadvantage during combat (see the section Combat).

A Ship may carry one or more Treasures. Treasures do not change the number of Combat Points, unless that is a specific Treasure Effect.

If a fleet is destroyed, any treasure it is carrying falls onto the world, but cargo is destroyed.

Combat

A fleet has one attack point per ship, unless it is carrying cargo, in which case the fleet has one attack point for every two ships.

A fleet has one defence point per ship.

Fleets in ASSAULT mode double their Attack Points.

An attacking fleet causes casualties on a defending fleet, according to this table:

Ratio of attack points to Defence Points Advantage
less than 1:1 one casualty for every two Attack Points
1:1 but not 3:1, OR in ASSAULT strategy one casualty for every Attack Point
3:1 or above no casualties, and the defending fleet is captured at the end of the resolution phase

Fleets attacking the same defending fleet combine their attack points to calculate ratios.

Combat is resolved simultaneously for both sides.

Fleets may bombard planets instead of attacking other ships. It takes 5 attack points to destroy one unit of population or industry. Ratios of attackers to defenders are not used in bombardment.

Ambush

Ambush is an attack during the movement phase, with double attack points, against ships attempting to move past the world. Ambushed fleets do not fire back in the movement phase. Ambushed fleets will stop movement in the world where they are ambushed. See the movement phase orders for details, and the Strategy section for strategies which will prevent an ambush. A fleet may participate in multiple ambushes, one per fleet attempting to pass the world.

Capture

If an enemy world has no friendly fleets (not counting fleets in EVASION strategy), and their population or industry are bombarded (even with a single ship), then the world will be controlled by the attacking player at the end of the resolution phase. If it has just been captured, the world cannot participate in actions during the resolution phase.

Strategy

A Fleet will have a Strategy. If a fleet is not given a strategy, it will have the ATTACK strategy if ordered to attack, otherwise it will have DEFEND strategy. You can change a fleet's strategy, and the new strategy takes effect before the combat is resolved. The Strategies are:

  • DEFEND
    • You can't order a DEFEND strategy; it happens automatically for fleets not ordered to attack or move, and not given an explicit strategy or supply route.
      • Double Defence Points
      • Attack all fleets that attack it, with no limit on the number of attacks
    • If this fleet survives the turn, no enemy in the same world may
      • transfer cargo,
      • transfer treasure, or
      • bombard a friendly world.
  • ATTACK
    • Standard attack and defence points
    • Will capture fleets if 3:1 ratio of attack to defence points is reached. Captured fleets will not be damaged in the attack – they surrender to the attacking player.
  • SUPPLY
    • The supply strategy is applied when a fleet is given an "S" order. See "Resolution phase orders."
    • Cannot participate in an ambush
    • Cancel this strategy by giving the fleet an attack order or a movement order.
  • ASSAULT
    • Double attack points
    • Halve Defence Points
    • Cannot capture fleets, or be captured.
    • Cannot move away on the movement phase
    • Cannot participate in an ambush
  • PURSUIT:
    • The fleet will follow any target fleet if the target moves in the movement phase.
    • A ship with the pursuit strategy cannot be given a movement order
  • HIDE
    • Cannot attack
    • Double defence points
    • Will not lose more than half of all ships in one turn
    • Immune to capture
    • Cannot participate in an ambush
    • Cannot prevent the world from being captured
  • INTERDICT
    • Same as HIDE but will immediately and automatically attack any fleet which
      • attacks a friendly world's population or industry
      • transfers rm to/from an enemy world
      • is built on the world
    • Fleets which INTERDICT and perform an automatic attack lose all benefits of the HIDE strategy.
    • Automatic attacks can occur any number of times during the turn.

Notes on interdiction

An interdicting fleet is staying out of sight, but will fight any ship created on the interdicted enemy world.

An interdicting fleet is limited in the amount of damage it can inflict on enemy fleets – only ships created in that turn can be destroyed. For example, a fleet of 10 ships can destroy five ships built on an enemy world which creates 10 ships and transfers them to a fleet of 200.

Fleets attacked by interdicting fleets will automatically return the attack, with half the normal attack points, but cannot capture.

Orders

Combat phase orders

Order Description
F<fleetId>XA Set the fleet with the given fleet Id into ASSAULT mode.
F<fleetId>XP Set the fleet with the given fleet Id into PURSUIT mode.
F<fleetId>XH Set the fleet with the given fleet Id into HIDE mode
F<fleetId>XI Set the fleet with the given fleet Id into INTERDICT mode
AF<fleetId>F<enemyFleetId> Attack the enemy fleet. Contributes all of the fleet's Attack Points to the destruction of ships on the enemy fleet.

Bombardment phase orders

Order Description
AF<fleetId>P Attack the enemy world's population. If any ships in Interdiction mode survive after fleet combat is resolved, they combine their Attack Points in a free attack against .
AF<fleetId>I Bombard the enemy world's industry. If any ships in Interdiction mode survive after fleet combat is resolved, they combine their Attack Points in a free attack against .

Resolution phase orders

Order Description Interdictable
F<fleetId>L<count> Load <count> raw materials Yes
F<fleetId>L(<treasureId>) Load the treasure with the id <treasureId> onto the fleet <fleetId> Yes
F<fleetId>U<count> Drop <count> raw materials Yes
F<fleetId>U(<treasureId>) Unload the treasure with the id <treasureId> from the fleet <fleetId> onto the world below Yes
T<count>F<fleetId1>F<fleetId2> Transfer <count> ships from <fleetId1> to <fleetId2> No
T(<treasureId>)F<fleetId1>F<fleetId2> Transfer the treasure with the id <treasureId> from fleet <fleetId1> to fleet <fleetId2> No
B<count>F<fleetId1>W<worldId> Build <count> ships on world <worldId> and either create a new fleet called <fleetId1> or add the ships to an existing fleet called <fleetId>. Raw materials dumped on this world will be available for construction, and raw materials loaded off this world will not be available for construction, in the same turn. Yes

Final phase orders

Order Description Interdictable
S<fleetId1>W<worldId> Load all available raw materials into <fleetId1>. This fleet will move to the world <worldId> in the movement phase. The fleet will have the SUPPLY strategy. When the fleet arrives at the destination, it will unload all available raw materials at the destination world. In the movement phase, it will return to the source world, unless the source world does not have a reverse connection to the destination world. Yes

Fleets with "Interdictable" orders can be attacked in the Resolution phase by any surviving enemy ships in INTERDICTION mode. Interactions between fleets and their worlds are all "interdictable".

Movement phase orders

Order Description
M<fleetId>W<worldId> Move the fleet given by fleetId to the world worldId
M<fleetId>W<worldId0>W<worldId1> Move the fleet given by fleetId to the world worldId0, and from there to world worldId1. Any fleets with DEFAULT or INTERDICTION strategy at worldId0 will ambush this fleet during the movement phase.
M<fleetId>W<worldId0>W<worldId1>W<worldId2> Move the fleet given by fleetId to the world worldId0, then moving to worldId1 and from there to world worldId2. Any fleets with DEFAULT or INTERDICTION strategy at worldId0 or world1 will ambush this fleet during the movement phase.
RF<fleetId1>F<fleetId2> Rename the fleet named fleetId1 as fleetId2 at the end of the movement phase. The fleet should still be referred to as fleetId1 in all orders in this turn, and referred to as fleetId2 at the start of the next turn

Movement more than three worlds in one turn is impossible.

Treasures

Not an exhaustive list of treasures, but these are the treasures with well-known effects. Other treasures are possible!

🧛 Staff of the Vampire ,T<VAM>

When a fleet carries this treasure and bombards a population (doesn't matter if friendly or enemy) the number of population killed is converted to ships on the fleet.

✝️ True Cross ,T<CRS>

If carried by a fleet or stationed on a world, and a fleet carrying the Staff of the Vampire starts the combat phase on the same world, then the Staff of the Vampire, the fleet carrying the Staff of the Vampire, and the True Cross are all destroyed.

🤬 Greater of Two Evils ,T<G2>

Will appear on unowned worlds. In the resolution round, a fleet carrying this treasure will lose half its ships, round up. A world carrying this treasure will lose half its population, round up. This treasure will transfer itself to the largest fleet at the current world, at the end of the resolution phase.

😡 Lesser of Two Evils ,T<L2>

A world carrying this treasure will lose 1 industry in the resolution round. A fleet carrying this treasure will lose 1 ship in the resolution round. A fleet carrying both the Greater and Lesser of Two Evils will disappear into the pits of Hell after the resolution phase.

💀 Magnus Morbus ,T<MM>

An enemy fleet at the same world as a fleet carrying the Magnus Morbus will lose 1 ship in the resolution phase.

👀 Summa Visionis ,T<SV>

A fleet carrying this treasure will treat fleets with the EVASION strategy as if they were following the DEFAULT strategy. This treasure is destroyed if the fleet carrying it is destroyed.