MegaTraveller Ship Combat Rule Extensions

as used in the Lunion Campaign

(Note: Any situation not covered by these rules below is to be taken as following the MegaTraveller rules.)

1. Definitions and Restrictions

1.1 Skill levels

Only "available" crewmembers can apply their skill levels to a task.

1.2 Pilot Skill vs. Ship Agility

Pilot skill may be substituted for the ship's Agility rating in any roll.

2. Initiating Combat

2.1 Tactical Pools

2.1.1 Determining the Tactical Pools

For each side, determine Fleet Tactics Pool: For each ship, determine Ships Tactics Pool: Note that the tactical pools may change during battle as a result of casualties.

2.1.2 Using the Tactical Pools

Before any appropriate roll, any number of tactical points may be expended as a positive or negative DM to that roll.  The Fleet Tactics Pool may be used on any roll for that side; the Ships Tactics Pool may be used on any roll for that ship.  Neither may be used on tasks covered by the Personal Combat Rules.

Tactical points may not be used to exceed the +8/-8 maximum DM limit.  They may not be carried over between combat rounds.

2.2 Initial Positions

The referee should set up the map to show Current and Last markers for each ship in the combat to represent the initial position and velocity.  The referee, at his discretion, may merely note the position and velocity for non-player ships not yet discovered; such ships may remain hidden until they reveal themselves through weapon, sensor, or communicator activity or by other means.

2.3 Surprise

2.3.1 Determining Surprise

An attempt to achieve surprise may be made once by the side initiating the hostile move, if there is one.
To determine if an attacking side has surprise
Difficult, Leader, Sensor Ops (confrontation).
Referee: Success at this task provides the attacking side with the benefits of surprise.  Use the best Leader and Sensor Ops skill levels from available crew members of each side. 

If this task fails, both parties are considered to be aware of each other.  If any mishap occurs, the defending side has surprise instead. 

The task difficulty may be adjusted by the Referee to account for individual situations.

2.3.2 Benefits of Surprise Avoiding combat
A side with the element of surprise may elect to end the combat before it begins by so stating. Free attacks
A side with the element of surprise may attack freely until surprise is lost.  All craft of the side with surprise may make one attack each, to which the other side may not respond or react.  If surprise is not then lost, each craft of the side with surprise which can fire may make another attack, and so on until surprise is lost or the round is complete.  If surprise is still not lost at the end of the round, another round of surprise combat may be enacted.

2.3.3 Losing Surprise

Surprise is lost when the attacking side reveals itself, or when any unit in the other side gives the alarm in some manner.

Spinal Mount fire automatically alerts the enemy to an attack; turret and bay fire may not.  Any unit that is hit but not rendered inoperative may raise the alarm through normal communications.

If the alarm is not raised in this manner, an unattacked unit may see the attack and raise the alarm.  To do so, that unit must be conducting sensor operations as part of their pre-combat procedure.  This task may be attempted after one complete surprise attack (within the round) by the attacker.

To raise the alarm in a surprise attack
Difficult, Leader, Sensor Ops.

At the moment surprise is lost, the combat round ends and normal combat takes over.

3. The Combat Round (General)

The side with the largest Tactical Points Pool has Initiative for that round.  The side with Initiative selects which side is to go first in that round.

Once a side has been selected, one unit from that side may take its turn.  The unit may move, make sensor scans, and make attacks as described below.  Any attacks take effect immediately.

Once the unit's turn is finished, one unit from the other side may take a turn.  Turns alternate in this manner until all units on all sides have taken a turn, whereupon the combat round is over and a new combat round begins.

A unit from the opposing side that has not yet taken a turn can choose to interrupt another unit's turn and take their turn in the middle of that unit's turn.

To interrupt another unit's turn
Routine, Agility (safe).
Referee: If the task is successful, it becomes the interrupting unit's turn, and it takes its actions for the combat round.  A failed interrupt roll has no penalties, and mishaps are ignored.

Interrupts are subject to the following restrictions:

4. Ship Combat Operations

This sections describes the actions a unit may make during its turn.

4.1 Movement

4.1.1 Performing Movement

Each ship is represented by two markers, one marking the Current position and one marking the Last position.  To move a ship:
  1. Using the Placeholder, apply Last->Current vector to Current position.
  2. Move Last position marker to Current position.
  3. The Placeholder may now be moved by a number of hexes up to the manoeuvre drive rating of the ship.
  4. The ship's move is made by moving the Current marker through the hexes along a direct line from Last to Placeholder.
  5. The Placeholder is replaced by the Current marker to complete the move.
Note that movement is not affected by damage sustained during the move.

4.1.2 Breaking Lock-On

Once during a ship's movement, the pilot may attempt to break an enemy sensor lock-on.  All enemy lock-ons are affected by this one task; there is no need to break each lock-on separately.
To break enemy sensor lock-on
Difficulty, Off=DefDM, Pilot; Def=Computer Model, Sensor Ops. 
Range Difficulty
Visual Formidable
Near Difficult
Far Routine
Extreme Simple
Success Lock broken
Exceptional Success Location broken
Referee: Only one attempt is permitted per combat round.  Use the most effective enemy lock-on when determining the DM's.  If the task succeeds, all lock-ons on the ship are broken.  If exceptional success is achieved, the ship has been lost by all sensors and a sensor scan must be made to locate the ship.

4.2 Sensor Operations

Sensors must locate a target and lock onto it before it can be fired on.  The sensor difficulty is recorded on the ship's description sheet.

At any point in its movement, a unit may declare it is performing a sensor task.  Multiple sensor tasks take time; to reflect this, the sensing unit must forego the firing of one weapon battery for every sensor task performed, except that one sensor task costs nothing.

4.2.1 Locating the Target

Before a lock-on can be attempted, the sensors must locate the target:
To locate a unit using sensors
Difficulty, Off=Computer Model; Def=Range (confrontation)
Extreme Failure Scan failed
Failure Target located if Strong/Large
Success Target located if Moderate/Medium, Strong/Large
Exceptional Success Target located
Referee: Use the most favorable sensor scan difficulty level from those on the ship.  Use the number of hexes from the sensing unit to the target unit as a negative DM.  Optionally, a character may use Sensor Ops skill in place of the computer number.

4.2.2 Locking Sensors on the Target

Sensors are locked onto a target using the following task:
To lock on a target using sensors
Difficulty, Off=Computer Model; Def=Range (confrontation, uncertain)
Referee: Use the mos favorable sensor pinpoint difficulty level from those on the ship.  Use the number of hexes from the sensing unit to the target unit as a negative DM.  Optionally, a character may use Sensor Ops skill in place of the computer number. 

If the task fails, sensor lock-on failed, but some benefit may still be gained, as follows: 

Some Truth Give unit displacement, power, but incorrect type
Total Truth Give unit displacement, power, and correct type

Once a lock-on has been established on a target, all units on the same side may share that lock-on and may therefore fire on the target without performing sensor tasks themselves.  To share a lock-on, a unit must be able to communicate effectively with the unit that performed the lock-on.

A lock-on persists until the target breaks the lock-on (see above).

4.2.3 Actions Affecting Sensor Location/Lock-on

These actions assume the the target in question has operational sensors. Performing active sensor operations
A unit which performs an attempted scan or lock-on on a target will reveal its location as if the target had performed an exceptional success sensor scan on that unit. Firing High-Signature Weapons
Firing certain high-signature weapons at a target will reveal the location of the unit as if the target had performed an exceptional success sensor scan on that unit.  These weapons are all Energy Weapons (Plasma and Fusion). Successful Attacks on a Target
Certain weapons will reveal the firing unit as if the target had performed an exceptional success sensor scan on that unit.  These weapons are Energy Weapons, Laser Weapons, and Particle Accelerators.

4.3 Fire Combat

The firing unit may fire at any enemy unit on which it has a current lock-on, using any of the offensive batteries on the ship.  It may fire as many or as few batteries as desired at any combination of target units.  It is not required to fire at all.

4.3.1 Sequence of Fire

Fire against each target occurs in the following sequence:
  1. All batteries which are to fire at that target muct be stated.
  2. A task is performed for each battery to determine if it scored a hit.
  3. For each battery that achieved a hit, a task is performed to determine if the hit penetrated the defensive fire of the target.  Each battery fired by the target ship as defense may not be fired again when it takes his turn, i.e. each battery may fire only once during a particular combat round.
  4. A task is performed for each remaining hit for each passive defence that must be penetrated.
  5. Damage is inflicted for each hit that penetrates all defences.

4.3.2 Defensive Weapons

Defensive weapons (sandcasters, repulsors, beam weapons used as missile defence, or proton beams against antimatter missiles) must be allocated against the hits of specific batteries.

Passive defences (all screens and configuration) resist every battery that hits, after active defences have taken effect.

4.3.3 Determining Range

Range is determined by counting the shortest path of hexes between firing unit and target.  The number of hexes is compare to the range table:
Visual 1 hex
Near 2 hexes
Far 3 - 10 hexes
Extreme 11+ hexes

4.4.4 Weapon Fire Tasks

To hit a target in spaceship combat
Off=Computer model, Weapon Table DM, Range DM, Skill DM; 
Def=Def DM (confrontation). 

Range DM: 

Lasers -1 if beyond Near range (worse attack)
Missiles +1 if beyond Near range (better attack)
Meson -2 if beyond Near range
Energy Cannot fire beyond Near range
Tractors Cannot attack beyond Near range

If range is Extreme, -1 per 10 hexes (drop fractions)

Skill DM: 

Gunnery skill / 2, round fractions down
Gunnery skill may be used directly in place of Computer DM.
To penetrate a defense in spaceship combat
Off=Computer model, Skill DM; 
Def=Computer Model, Defence table DM, Skill DM (confrontation). 

Skill DM: 

Gunnery skill / 2, round fractions down
Gunnery skill may be used directly in place of Computer DM.
Referee: Energy weapons provide Off DM of +2.

4.4.5 Additional Direct Fire Notes Line of Sight
Attacks require a clear line of sight.  The line of sight consists of a straight line between the centre of the attacker's hex through the centre of the target's hex.  The line of sight may not pass through any obstructions.

Objects which can block the line of sight in open space include a star, planet, moon, or even a large asteroid. Pinpoint Location at Visual Range
When at visual range, a unit can specify that it is firing for pinpoint location damage.  If Exceptional Success is achieved, the damage on the table is rerolled until the specified location comes up; if Exceptional Success +2 is achieved, the location is hit with a critical hit; otherwise the shot failed to hit the location and is resolved as normal.


Each battery which hits has one roll on one or more damage tables.

5.1 Spinal Mounts

Spinal Mount weapons inflict one extra damage determination for each letter by which their UCP code exceeds 9.  The number of extra rolls is reduced by one for every 3 levels of armour the target has beyond 40; but the weapon always has at least one roll; Meson gun damage rolls are not affected by armour.

5.2 Critical Hits

[More to come...]

5.3 DMs for Damage Rolls

  1. For every 3 levels of armour over 40, apply DM -1 for all weapons on Surface Explosions table and all but Meson Guns on the Radiation damage table.
  2. Spinal Mount weapons apply DM +6.
  3. Nuclear Missiles apply DM +6 on Surface Explosion table.
  4. Pulse Lasers apply DM +2.
  5. Rolls resulting from other rolls, such as Interior Explosion from Surface Explosion, are unmodified.

5.4 Damage Results

Where the results must choose between more than one system, the system actually affected is chosen randomly between those still operational.

5.4.1 [More to come]

5.4.x Crew -N

This represents the number of crew sections rendered ineffective (likely dead) for at least the duration of the battle.  Upon reduction of the crew to below 50% of the initial level, the ship may no longer fire weapons or attempt repair; although it may use its passive defences, manoeuvre, or jump.  This result does not affect Frozen Watch or Ships Troops.

For PC ships, this may be individualized to specific damage to crew members.  In this case, determine the area of the ship affected by the attack, and consult the following:

Radiation Damage Each affected crewmember takes 1D + 1 hits, plus one hit for each UCP weapon factor over 9.
Interior Explosion The affected area is a non-critical section of the ship (i.e. probably less than an actual Crew-1 effect), but each affected crew member takes 2D hits.

Crew injury may also result incidentally from damage to other sections of the ship.

6 More to Come...