Space Empires — 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.

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.

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

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Game Rules

The Universe

The universe is a set of worlds connected via a galactic hyperspace network. Travel between worlds is only possible through the connections of this hyperspace network. The map may be a grid, a torus, a dodecahedron, or an organic spanning tree of interconnections.

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 DEFEND or INTERDICT 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.

• rms=22 the world has 22 points of Raw Materials Stored.

• rmp=10 the world produces 10 points of Raw Materials every turn.

• pop=31 the world has a Population of between 30 and 31 million.

  F2 10, I

Fleet F2, owned by Ming, 10 ships, INTERDICT strategy last turn.

F3 <BOSCO> 20/5, TGT=POP

An enemy fleet designated F3. 20/5 means 20 ships carrying 5 units of Raw Materials. TGT=POP means it bombarded population last turn.

F5 <BOSCO> 20, <-W2

Bosco's fleet of 20 ships. It arrived from world W2 last turn.

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

F4 was captured from Bosco last turn. X<BOSCO F-5> identifies the original owner and designation.

F9 <MING> 30, TGT=F5

F9 fired on F5 during the combat phase last turn.

F10 <BOSCO> -> W2

Bosco's fleet F10 left for W2 at the end of last turn. It is no longer here.

Movement

Fleets may travel from one world to another with the M order. You can move a ship up to three jumps from its origin in a single turn. For example:

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.
• A fleet which has just been created cannot move on the same turn as it was constructed. However, if ships are built onto an existing fleet, that fleet may still move in the same turn.
• 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.
• A fleet may be given one movement order per turn. Once it has moved, any further M order for that fleet is refused — three jumps is the limit for the turn, not for each order.

Jumping into unknown space

You may name any world in a jump path, including worlds you have never seen. Your fleet will fly as far along the path as the hyperspace network actually allows, and stop there.

MF1W2W7

If W2 connects to W7, the fleet arrives at W7. If it does not — or if W7 is not a world at all — the fleet stops at W2, and your report simply shows it at W2. If even the first jump is impossible, the fleet does not move, and nothing is reported.

You are never told which link was missing. A jump into the dark that goes nowhere looks exactly like having given no movement order, so guessing at world numbers cannot be used to chart space your ships have not reached. What a fleet learns, it learns by arriving: once it reaches W2, your report lists W2's connections, and you can plan the next jump properly.

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. 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 have two attack points per ship — ASSAULT replaces the cargo penalty rather than compounding with it, so an ASSAULT fleet has two attack points per ship whether or not it is carrying cargo.

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, in the combat phase

Fleets attacking the same defending fleet combine their attack points to calculate ratios. Combat is resolved simultaneously for both sides.

If a 3:1 ratio is reached but the defending fleet cannot be captured — because of its strategy (see HIDE, INTERDICT, ASSAULT), or because the attackers are in ASSAULT — the attack falls back to the 1:1 row instead: one casualty for every attack point. There is no outcome in which reaching 3:1 does less damage than falling short of it.

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. A fleet may participate in multiple ambushes, one per fleet attempting to pass the world.

If an ambush reaches a 3:1 or greater ratio of attack to defence points, the passing fleet is captured by the ambushing player instead of taking casualties, exactly as in Combat — unless the passing fleet's strategy makes it immune to capture (see Strategy), in which case it takes casualties as normal instead. A captured fleet stops in the world where it was ambushed, now under its new owner.

Capture

If an enemy world has no friendly fleets (not counting fleets in HIDE strategy), and their population or industry are bombarded (even with a single ship), then the world is controlled by the attacking player from the moment the bombardment lands, during the bombardment phase. A world captured this turn takes no part in the resolution phase that follows it — in particular, nothing can be built there that turn.

Strategy

Strategy names in this document match the ones the engine uses: ATTACK, DEFEND, ASSAULT, PURSUIT, HIDE, INTERDICT and SUPPLY. Earlier drafts called DEFEND "DEFAULT", HIDE "EVASION" and INTERDICT "INTERDICTION"; those are the same three strategies under older names.

A Fleet will have a Strategy, re-derived each turn from that turn's orders unless the fleet is given an explicit strategy order. If a fleet is not given a strategy, it will have the ATTACK strategy if it is ordered to attack or move, otherwise it will have DEFEND strategy. This applies even if the fleet had DEFEND from a previous turn: moving without an explicit strategy order forfeits the automatic DEFEND for that turn (and its doubled defence points, both in transit and at its destination), exactly as being ordered to attack does. You can change a fleet's strategy, and the new strategy takes effect before combat is resolved.

• DEFEND
  • 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.
• SUPPLY
  • Applied when a fleet is given an S order.
  • Cannot participate in an ambush.
  • Cancel by giving the fleet an attack or 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.
  • 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 into ASSAULT mode.
F<fleetId>XP	Set the fleet into PURSUIT mode.
F<fleetId>XH	Set the fleet into HIDE mode.
F<fleetId>XI	Set the fleet 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. Surviving INTERDICT ships get a free combined attack against <fleetId>.
AF<fleetId>I	Bombard the enemy world's industry. Surviving INTERDICT ships get a free combined attack against <fleetId>.

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	Yes
F<fleetId>U<count>	Drop <count> raw materials	Yes
F<fleetId>U(<treasureId>)	Unload the treasure with the id <treasureId> from the fleet 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 from fleet <fleetId1> to fleet <fleetId2>	No
B<count>F<fleetId1>W<worldId>	Build <count> ships on world <worldId> and create or add to fleet <fleetId1>. Raw materials dumped on this world will be available for construction; raw materials loaded off this world will not be, in the same turn.	Yes

Final phase orders

Order	Description	Interdictable
S<fleetId1>W<worldId>	Load all available raw materials into <fleetId1>. Move to <worldId> in the movement phase with SUPPLY strategy. On arrival, unload all raw materials. In the movement phase, return to the source world unless there is no reverse connection.	Yes

Fleets with "Interdictable" orders can be attacked in the Resolution phase by any surviving enemy ships in INTERDICT mode.

Movement phase orders

Order	Description
M<fleetId>W<worldId>	Move the fleet to world <worldId>
M<fleetId>W<worldId0>W<worldId1>	Move the fleet to <worldId0>, then to <worldId1>. Fleets with DEFEND or INTERDICT strategy at <worldId0> will ambush.
M<fleetId>W<worldId0>W<worldId1>W<worldId2>	Move the fleet through <worldId0> and <worldId1> to <worldId2>. Fleets at <worldId0> or <worldId1> with DEFEND or INTERDICT strategy will ambush.
RF<fleetId1>F<fleetId2>	Rename <fleetId1> as <fleetId2> at the end of the movement phase.

Movement more than three worlds in one turn is impossible, whether in one order or spread across several — a fleet moves once per turn. A fleet flies as much of its path as the hyperspace network allows and stops there, and is never told which link was missing; see Jumping into unknown space under Movement.

Treasures

🧛 Staff of the Vampire ,T<VAM>

When a fleet carries this treasure and bombards a population (friendly or enemy), the 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, its carrier fleet, 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 HIDE strategy as if they were following the DEFEND strategy. This treasure is destroyed if the fleet carrying it is destroyed.

Treasure clarifications

The rules above leave a number of treasure edge cases open — what becomes of a treasure when its carrier is destroyed, whether one follows a captured or renamed fleet, exactly how far the Summa Visionis sees, and when the resolution-phase effects land. Each is decided, and the reasoning written down, in Treasure clarifications.

Orders written by the AI

You may have a turn's orders drafted for you, and an empire that submits nothing in the opening turns has orders generated for it automatically. Those orders are ordinary order tokens, parsed and judged by exactly the same rules as typed ones, and the AI sees no more of the universe than your own report shows. When it is asked, what it is shown, and what happens when it fails, are set out in The AI orders processor.