Player rules for Domain of the Ancients

First published 17th January 2022 (Last Modified 21st February 2024)


This is a version of my play-by-mail game Domain Of the Ancients 2 (DOA2) (Footnotes are used to indicate where DOA2 is different from this set of rules). It is set in a very small globular cluster. Several hundred years ago an interstellar empire existed in the cluster, but after several medium sized disasters struck the empire it collapsed leaving little trace.

Now the main centres of population have rediscovered space travel and discovered both the technology to reach the stars and the large communication centres left by the Ancients. There was almost immediate panic when the communication centres revealed the existence of several other recovering population centres. Each empire quickly decided that it had to colonise as much of the cluster as possible before the others did!

Map Layout

The map is a hex grid 20 by 16 hexes in size (the equivalent of four Traveller subsectors). The cluster has exactly one hundred habitable systems. The centre of the cluster is more densely populated with habitable systems than the edge of the cluster.

Each hex is the equivalent of one parsec (3.26 light years) across and contains at most one habitable system. A turn is ten years in length.


At the start of the campaign each empire has its capital (a class 20 colony) and no initial stock of production points. On the first turn each empire must select its favoured technology area. Any research in this favoured area is doubled in effect.


A player gives orders for each complete turn. Each turn phase happens simultaneously for all players. The phases are:

  1. Receive reports from ships and systems on the resolution of orders in the previous turn (if any)
  2. Collect Production Points
  3. Issue orders to existing ships
  4. Spend Production Points1
  5. Move existing ships and resolve any conflicts

Receive Reports

As your previous turn's orders are processed you'll be provided with the reports from your ships and planets on the resulting events (both from your orders and those of the AI players)

Collect production Points

Every planet that a player controls will be assigned a class number. This is an indication of the industrial size of the planet. Each empire's homeworld (initial colony) starts as a class 20 planet. Each planet creates production points (PP) equal to twenty times its class number. Thus, for example, on the first turn, each empire will get 400 PP. If a colony is interdicted (only hostile ships are in the hex of the colony) its production points are lost unless the it is the capital of the empire. If the empire capital is interdicted the empire loses all production from all other colonies.

Issue Orders to Existing Ships and Colonies

Orders are issued to your existing ships (new ships are built in a later phase of the turn). The orders cannot instruct ships to travel outside of the empire's communication grid. If a ship is outside of the communication grid at this phase of the turn (for example if a colony has been captured thus reducing the range of the communications grid), the ship will travel as quickly as possible towards the empire's homeworld until it returns to the communications grid2.

Spend Production Points

There are many things on which the production points can be spent:

  1. Improving a colony
  2. Improving Technology Levels
  3. Buying Ships
  4. Buying Planetary defences

Improving a colony

A colony can be improved one class by spending production points equal to twenty times its current class (i.e., by spending all of its production for one turn). To do this the colony needs to be at class 5 or higher (colonies below class 4 can only be improved by landing colony ships on it)3.

Improving Technology Levels

An empire is rated in several different technology areas. These indicate how advanced the empire in those technology areas. Each empire starts at Tech Level 1 in all areas. An empire improves in an area by spending production points on research in that area. As certain thresholds of total research expenditure are reached new pieces of equipment will become available to the empire. Each area of technology has its own threshold levels but, as a guide, Tech Level 2 will be reached somewhere between 180 and 270 points and Tech Level 3 at a threshold between 800 and 1,600 points. Production points spent in research in an empire's favoured technology area count double.

The various technologies and their initial benefits are:

Power Plant
Research into mechanisms to produce power for starships. Initially allows the construction of starships using chemical power plants.
Jump Drive
Research into long range travel. Initially allows starships to be constructed with Jump-A Drives
Maneuver Drive
Research into short range travel. Initially allows starships to be constructed with Maneuver-A Drives
Research into communication equipment. Initally allows ships to communicate with planets as long as the ships are within one hex of the planet.4.
Ship Size
Research into the construction of bigger star ships. Initally allows the construction of starships with up to 10 blocks in size.
Planetary Defences
Research into ways to defend planets. Initally allows the construction of marine companies armed with projectile weapons5.
Ship Weaponary
Research into better ways of throwing energy from starships. Initially allows Laser Batteries to be fitted to ships6. A Laser Battery has a 1 in 6 chance of hitting during a phase of ship combat.
Ship Defences
Research into ways of stopping starships from being damaged. Initially allows ships to be fitted with armour blocks.
Research into ways of improving the control of Starships. Initially allows Level one computers to be added to the bridge of a starship. In a space battle, if all other things are equal, the ship with the better computer will usually win.
Research into Ancient Artifacts left behind. The initial discovery is that of the communications station. This allows an empire to talk to any (or all) other empire(s). Both the sender and receiver only receive the contents of the message (i.e., not its origin or destination).7

Buying Ships

A player can either purchase standard designs of ships or design their own ships. New ships can arrive at the capital or at any class 20 (or better) colony. The first ship of a new design costs double unless it is the first ship using a new ship size technology (the first ship ever built counts as using the Tech Level One ship size and so its price will not be doubled).

Buying Planetary Defences

Marine companies can be built at any colony and cost 10 production points each.

Capturing colonies

To capture a colony belonging to another empire you must first gain space superiority over the hex (i.e., all enemy ships must have either been destroyed or have fled the hex). At this point marines can be landed at the colony. If the attacking marines destroy all the defending marines the colony is captured.

If only space superiority is achieved the colony is interdicted. If a colony is interdicted its production can only be spent at the colony. If an empire's capital is interdicted this restriction applies to all colonies (including the capital) of the empire.

If a colony is conquered the colony loses one class. If the colony was only a class one colony the colony is destroyed - along with the attacking marines. If the colony was class two or better before being conquered the colony now belong to the attacking empire and its (reduced) production will be available on the next turn.

Following any ground combat any attacking marines that were lost remain destroyed and will need to be repurchased by the attacking empire if they wish to bring the marine barracks of the attacking ships up to full strength.

Ship Design

Ships are designed by adding together a number of building blocks to make the ship. The total number of blocks gives the size of the ship. For example all ships up to size 10 (The maximum ship size permitted by the starting Ship Size Tech Level) cost 50 PP for the hull.

The following blocks are available at the initial Technology Levels:

A minimum of one bridge is required on a ship regardless of its size. Additional Bridges can be fitted (as backups) at a cost of 10 PPs. In addition each bridge can be fitted with computer systems. A Level 1 Computer can be fitted to a bridge at a cost of 10 PPs and uses one Energy Point to be operated in normal space. Note that backup bridges must be also be powered. A ship with no bridges is destroyed.
Chemical Power Plant
Generates 12 Energy Points and can be fitted for a cost of 10 PPs.
Jump-A Drive
A Jump Drive is required if the ship is to move between hexes. It requires 10 Energy Points while operating and generates 10 Jump Points. A Jump-A drive block costs 5 PPs. Note that power is provided to the bridges on a ship before the jump drives are powered.
Maneuver-A Drive
Allows the ship to maneuver and is required for all ships. It requires 10 Energy Points while operating (i.e. a ship does NOT need to power both a Jump Drive and the Maneuver Drive simultaneously) and generates 10 Maneuver Points. It costs 5 PPs to fit a Maneuver-A Drive. Note that power is provided to the bridges on a ship before the maneuver drives are powered.
Laser Battery
Requires one energy to operate and 5 PPs to fit. A laser battery has a one in six chance of hitting an enemy ship during a phase of ship combat. A laser battery that hits destroys an armour block on the enemy ship if it has any. If the enemy ship has no armour blocks when the laser hits a random block on the target is destroyed. Note that power is provided to a ships's bridges and maneuver drives before power is provided to any weapons.
Armour blocks cost 5 PPs to fit.
Marine Barracks
Barracks for a single company of marines. It costs 11 PP to fit a marine barracks to a ship. The barracks includes all the facailities needed to land the troops when the existing ground forces object to the arrival of the marines (however there must be no hostile space forces remaining in the system). The cost of the barracks includes the cost of the marines. An existing marine company at a colony (not from other ships) may be moved into empty barracks when orders are issued to the ship.
Colonisation System
Each colony system costs 30 PPs to add to a ship and occupies 6 blocks. If the ship is at a system with either no colony or with a colony of class 5 or lower the ship may be destroyed to establish a new colony or improve the existing colony. For every colonisation system on the destroyed vessel(s) the colony gains one class level (Note that if the colonisation system has been damaged or destroyed it will not be used during the colonisation).

Jump Range

The maximum distance a ship can jump in a single turn is determined from its jump points. The number of jump points generated by the ship is divided by its size and rounded down. A ship cannot jump (in a single turn) further than this jump range. In addition the ship may not jump from inside the communications range of the empire to outside of that communications range. If a ship finds itself outside of the communications grid (for example if a colony is captured by an opposing empire) it will self-destruct to prevent its capture.

Combat Speed

The combat speed of a ship is determined by its maneuver points and its computer (if any). Take the Maneuver Points generated by the ship and divide by its size and round down. Then add the level of the computer system to that value to get its combat speed. Note all ships must have a speed of at least one before the computer level is added.

Example Tech Level 1 Ships

Colony Ship

Description Cost Energy
Hull (with Bridge) 50
Chemical Power Plant 10 12 EPs generated
Jump-A Drive 5 10 EPs in jump space
Maneuver-A Drive 5 10 EPs in normal space
Colonisation System (occupies 6 blocks) 30
100 PPs Jump-1, Combat Speed-1

The only possible design of a colony ship at Tech Level 1.


Description Cost Energy
Hull (with Bridge and TL1 Computer) 60 1 EP in normal space
Chemical Power Plant 10 12 EPs generated
Chemical Power Plant 10 12 EPs generated
Jump-A Drive 5 10 EPs in jump space
Maneuver-A Drive 5 10 EPs in normal space
Maneuver-A Drive 5 10 EPs in normal space
Laser Battery 5 1 EP in normal space
Laser Battery 5 1 EP in normal space
Laser Battery 5 1 EP in normal space
Armour Block 5
115 PPs Jump-1, Combat Speed-3

The example fighter is designed to be an effective weapon against other hostile ships. Its high speed (from the pair of maneuver drives and TL1 computer) gives the example fighter sufficent oomph to drive off ships such as the example colony ship.

System Defence Boat

Description Cost Energy
Hull (with Bridge and TL1 Computer) 60 1 EP in normal space
Chemical Power Plant 10 12 EPs generated
Chemical Power Plant 10 12 EPs generated
Chemical Power Plant 10 12 EPs generated
Maneuver-A Drive 5 10 EPs in normal space
Maneuver-A Drive 5 10 EPs in normal space
Maneuver-A Drive 5 10 EPs in normal space
Laser Battery 5 1 EP in normal space
Laser Battery 5 1 EP in normal space
Laser Battery 5 1 EP in normal space
120 PPs Combat Speed-4

The example system defence boat is designed to defend the homeworld from enemy ships. While it is unable to jump and has also sacrified the armour from the fighter design, it is quicker than than the example fighter and so will be able to fire on that fighter before it can respond.

Ship Combat

Combat proceeds in rounds until one side is destroyed, is captured, or retreats. Each round is resolved as a series of phases numbered from 1 to the highest combat speed of any ship involved in the combat. Each round of combat starts with the highest numbered phase and then counts down in phases until phase 1 is completed.

In each phase a ship may fire if its combat speed equals or exceeds that of the phase. Within a single phase firing is simultaneous. Alternatively a ship may retreat at the end of the round of phases. A retreating ship is counted as having a forced jump in the next turn8 (so only ships with a Jump Range of more than zero are permitted to retreat. If a ship loses a jump drive block or power plant due to enemy fire its jump range is recalculated before determining if it can retreat). A retreating ship will jump back to the hex it was in during the previous turn (which could be the same hex if the ship didn't move) ,

Shipboard combat

There is no shipboard combat9.

Example ship Combat

As an example take a combat between the example fighter and the example system defence boat. The combat speed of the example fighter is 3 (20 Maneuver Points divided by its size of 10 and then plus one for the computer fitted to the bridge). The example system defence boat has a combat speed of 4. Each round of combat will therefore have four phases.

Phase 4
In this phase only the system defence boat can attack. It has three laser batteries, so rolls 1d6 three times to see if it can hit. It scores one hit, which it destroyed the fighter's armour block.
Phase 3
Both ship can now fire and do so simultaneously. The system defence boat and fighter (with its four lasr batteries) both miss.
Phase 2
Again both ships can fire. Both ships score one hit. The system defence boat destroys one of the fighter's laser batteries while the fighter destroys one of the system defence boat's power plant. The energy balance of the system boat is recalculated and its combat speed is reduced to 3 (Only two of its maneuver drives can be fully powered and so it now only generates 20 maneuvr points - At this reduced speed it can still power all three of its laser batteries though).
Phase 1
Even at its reduced speed, the system defence boat is still able to act in Phase 1 so both ships can fire. Again both ships score one hit. The system defence boat destroys the bridge of the fighter and hence destroys the fighter. Since firing and damage is simultaneously the fighter still gets to damage the system defence boat and destroys one of its laser batteries.

Ship repair

Ships can be repaired if the ship is at a class 20 or better world. The repairs are conducted by paying the cost of the destroyed blocks. So taking the system defence boat from the example combat it can be repaired for a cost 15 PPs (10 PPs for the power plant and 5 PPs for the laser battery). A ship cannot be ordered to jump if it is being repaired. If the ship is further damaged by more combat during the next turn the repair is aborted (at no cost). The funds for the repair are removed from the funds carried forward (and, if necessary, part of the next turns production will be used to cover any shortfall in the carried forwrad funds).

Obsolete ships may be scrapped anywhere. Any undestroyed parts are destroyed and 40%11 of their value is given as a refund. No refund or reuse is possible for blocks already destroyed in combat. So, as an alternative, the damaged system defence boat from the example combat could be scrapped and 26 PPs refunded (Original cost of 120 PPs but the damaged blocks remove 15 PPs from that value giving 105 PPs. 40% of this is 42 PPs). The refunded production points are provided as part of the carried forward funds (i.e., the scrap value cannot be spent until the following turn). Of course if the ship is damaged during the turn its scrap value will be correspondingly reduced (ships that are forced to retreat will still be scrapped and the scrap value will still be refunded).

Ground Combat

Ground combat is resolved in a series of rounds, In each round a percentile dice roll is made for each of the attacker and defender simultaneously. This percentage is then multiplied by the size of the force and rounded down. The result is removed from the opposing force. When resolving combat on a colony this is repeated until one force is eliminated.

Example gound combat

A colony is defended by 50 marine companies and is attacked by 20 marine companies

Round 1
The defender's dice roll is 11 and so the attackers will lose 10 companies. The attacker's dice roll is 82, so the defenders lose 16 companies. At the end of this round the defenders have 34 companies while the attackers have 9 companies
Round 2
The defenders dice roll is 86 so the attackers will lose 29 companies. The attackers roll 34 so the defenders lose 3 companies. At the end of this round the defenders have 31 companies while the attackers have been destroyed.

Capital Planets

As described in Collect Production Points, if an attacker gains space superiority over an empire's capital world (but is unable to win the ground combat to capture that world) the defender only gains production points from the capital (all other production for the turn is lost) as long as the the capital remains interdicted.

If an attacker conquers the world the defender is eliminated from the game12. If this happens all of the remaining colonies in the defending empire are also removed from the game at the end of the game turn.

Designer's Advice

This are probably obvious points from the above:

  1. Setting up new colonies and improving small colonies is the cheapest way to boost your empire's production (though conquering the colonies of other empires is quite good too!).
  2. If you're starting at the edge of the map you're likely to have very few worlds within one hex of your starting position - there are less hexes in which those other worlds could be present AND the generation system favours putting the worlds towards the middle of the map. Conversely if you're in the middle of the map it's quite likely that another empire's starting world is quite close to yours.
  3. The technology progression and combat rules are designedso that quality will, in general, be better than quantity when it comes to both ships and marines.
  4. Combat ships will want your best possible computer system
  5. If a ship is obsolete then scrap it - the 25% refund will be better (as a general rule) than using it as laser battery fodder.
  6. As a reminder in this version of the game if you lose your starting world you lose the game immediately


  1. DOA2: Ships move before the production points were spent and hence could interrupt that spend (for example by preventing new ships from being built)
  2. DOA2: Ships have standing orders allowing them to travel outside of the communications grid as long as they don't run out of fuel
  3. DOA2: A colony can be improved more that one class in a turn
  4. DOA2: Allows the purchase of sensor blocks which are installed on ships and allowed the scanning of hexes while the ship was in jump.
  5. DOA2: Marine company armaments were covered by weaponary
  6. DOA2: The weaponary technology covered both ship-borne and marine-borne weapons. The initial Weaponary technology also allowed Missile Batteries which could be for planetary bombardment, a concept not used here
  7. The archaeology advances have been revised and may be different from those in either DOA2 or DOA1
  8. DOA2: Ships could retreat during any phase where the ship would have been permitted to fire
  9. DOA2: Ship board combat was permitted if a vessel's maneuver speed was reduced to zero
  10. DOA2 allowed vessels to be captured and then either refitted (for use by the capturing empire) or deconstructed (to provide the capturing with additional technological research)
  11. DOA2: Only 25% of the ship's value was given as a refund
  12. DOA2: The defender remains in the game and must choose a new capital on the next turn - only if all of an empire's colonies are captured is the empire eliminated from the game