Each turn in space combat lasts six minutes.
If two vessels randomly encounter each other while travelling, the encounter will begin at Very Long range. More often, ships engage near a planet, where the range is Short or Medium.
- Adjacent: <1 km
- Close: 1 km–10 km
- Short: 10–1250 km
- Medium: 1250 km–10,000 km
- Long: 10,000 km- 25,000 km
- Very Long: 25,000 km – 50,000 km
- Distant: 50,000 km+
| Range | Distance | Thrust to Change | Example |
| Adjacent | <1 km | 1 | Docked ships |
| Close | 1 to 10 km | 1 | Nearby vessels |
| Short | 10 to 1250 km | 2 | Ships in same orbital path |
| Medium | 1250 to 10,000 km | 5 | Surface to orbit |
| Long | 10,000 km to 25,000 km | 10 | Near a planet |
| Very Long | 25,000 km to 50,000 km | 25 | Within jump limit |
| Distant | 50,000 km+ | 50 | Distant ships |
| Weapon | Adjacent | Close | Short | Medium | Long | Very Long | Distant |
| Pulse Laser | -1 | -1 | +0 | -1 | -2 | -3 | Out of range |
| Beam Laser | -2 | -1 | -1 | +0 | -1 | -1 | -2 |
| Particle Beam | -3 | -2 | -1 | -1 | +0 | -1 | -1 |
| Fusion Gun | -2 | -2 | -1 | +0 | -1 | -1 | -2 |
| Meson Gun | -4 | -3 | -2 | -1 | +0 | -1 | -2 |
| Missiles (flight time) | - | - | 1 | 1 | 2 | 5 | 10 |
| Sandcaster | -2 | +0 | -2 | Out of range | Out of range | Out of range | Out of range |
Pilot: Flies the ship, responsible for changing course and for evasive manoeuvres.
Captain: Commands the ship, and can use Leadership and Tactics skills.
Drive Engineer: An engineer can be assigned to each of the M-drive and the J-drive.
Turret Gunner: Each turret has its own gunner. A character must choose which turret he is manning at the start of the combat.
Bay Gunner: Each bay weapon has its own gunner.
Damage Control: A character assigned to free-floating damage control can repair any system.
Marine: Prepares to repel boarders, or to board enemy ships.
Passenger: Passengers are all people aboard ship who are not assigned a position and are assumed to be waiting in staterooms.
[h=4]Automated Positions[/h] The ship’s computer can cover several positions if it is running the appropriate software:
Fire Control programs can either act gunners or aid existing gunners.
A ship equipped with repair drones and Auto-Repair software acts as damage control.
A ship running an Intellect program and Expert Pilot can be the pilot.
A ship equipped with repair drones and running an Intellect program and Expert Engineer (M-drive or J-drive) can be a drive engineer.
[h=2]Initiative[/h] Each ship in an engagement rolls 2d6 to determine their starting Initiative score. The ship with a greater Thrust score gains a +1 DM to its roll.
The commander of each spacecraft (or each fleet, if more than one ship is involved on each side) may a Tactics (naval) check. The Effect is added to the Initiative of the spacecraft (or fleet).
[h=2]Manoeuvre Phase[/h] In each manoeuvre phase, a ship can allocate Thrust either to movement (closing or increasing the range to a target) or manoeuvring. The amount of thrust needed to close or open by one range category is given in the Range Table – the number given is the amount of thrust needed to move from that range category to either a closer or more distant one. A ship can spend thrust over multiple rounds to close or open a range category.
If two ships are travelling towards each other, then add together the Thrust allocated by both ships to movement to see how close they are to changing range categories; if one ship is trying to escape from the other then subtract the lower Thrust from the higher value to work out the effective change in position – the faster ship will either gain slightly or pull away slightly.
Any thrust not allocated to movement is allocated to manoeuvring, which is done in the combat phase. Manoeuvring does not change the range to the target but allows the ship to position itself better for an attack or to avoid incoming fire.
[h=2]Combat Phase[/h] In each combat phase, a ship may manoeuvre, fire any of its weapons, or board enemy vessels.
[h=4]Manoeuvre[/h] A ship can manoeuvre, dodging and weaving to evade enemy fire or to position itself for a better attack. A ship may make a number of manoeuvre actions per combat phase equal to the amount of Thrust allocated to manoeuvring.
A manoeuvre action can be used to:
Dock with another vessel: The pilot must make a successful Pilot check. If the other ship does not wish to be docked with then make opposed Pilot checks; the ship trying to dock suffers a –2 DM. When docked, boarding actions can take place.
Help line up a shot: A pilot may attempt to aid his gunners by providing a stable firing platform along an optimum attack vector. The pilot makes a Pilot check to aid his gunners as per the normal rules on task chains.
Dodge incoming fire: Any leftover Thrust can be spent as a reaction to dodge incoming fire.
[h=4]Firing Beam Weapons[/h] To fire a beam weapon, the gunner must make a successful Gunner (turret) or Gunner (capital weapons) check, modified by the range to the target. When targeted by a beam weapon, the enemy ship may react by dodging, firing sand or triggering screens (see Reactions). A gunner may fire any or all of the weapons in his turret or bay but each turret or bay may only fire once per round.
If the attack is successful it will inflict damage. Damage is resolved after all attacks have been made in a round.
[h=4]Launching Missiles[/h] Unlike beam weapons, which travel at the speed of light and so hit the enemy vessel almost instantly, missile weapons take time to cross the gulf of space. Missiles travel at Thrust 5 towards their designated target and their position can either be tracked as additional craft in the battle or, for the sake of simplicity, they can be assumed to strike after a number of turns dependent on launch range:
| Range | Turns to Impact |
| Adjacent | - |
| Close | - |
| Short | 1 |
| Medium | 1 |
| Long | 2 |
| Very Long | 5 |
| Distant | 10 |
The gunner must make a Gunner (turret) or Gunner (capital weapons) check to determine how accurate the missile launch was. The effect of the Gunner check determines the chance that the missile will strike its target when it hits.
| Gunnery check | Missile to-hit roll | Gunnery check | Missile to-hit roll | |
| Failed With Effect –6 or less | 11+ | Succeeded With Effect 0 | 8+ | |
| Failed With Effect –2 to –5 | 10+ | Succeeded With Effect 1–5 | 7+ | |
| Failed With Effect –1 | 9+ | Succeeded With Effect 6+ | 6+ |
[h=4]Smart Missiles[/h] The missile to-hit roll for smart missiles is always 8+ and if they miss they make another attack every turn until they are destroyed with point defence, jammed with ECM or otherwise dissuaded.
[h=4]Boarding Actions[/h] If two ships are Adjacent or docked, then a boarding action can be attempted. If the ships are docked, then the attackers may cross over safely via airlocks. If the ships are merely adjacent, then the attackers must use thruster packs or small craft to cross over. While crossing, the attackers may be attacked with point defence weapons or by firing sand.
Once across, boarding actions can be resolved using the personal combat rules or the quick boarding rules.
[h=4]Special Attacks[/h] Several types of weapons have their own rules.
Meson Guns: Meson guns ignore armour and always roll on the Internal Damage table. Furthermore, they also automatically inflict a radiation crew hit in addition to any other damage.
Fusion Guns: Fusion guns inflict a radiation crew hit in addition to any other damage. The bonus radiation hit suffers a –DM equal to the ship’s armour.
Particle Beams: Particle beams inflict a radiation crew hit in addition to any other damage. The bonus radiation hit suffers a –DM equal to the ship’s armour.
Nuclear Missiles: Nuclear missile hits inflict a radiation crew hit in addition to their normal damage. The bonus radiation hit suffers a –DM equal to the ship’s armour.
Sandcasters: While the primary purpose of a sandcaster is to block incoming beam attacks, they can also be used as an attack. A sandcaster has a range of Close and inflicts 1 damage.
[h=2]Reactions[/h] A ship may react to incoming attacks. The following situations allow reactions:
- Targeted by a beam attack
- Incoming missile
- Attempted boarding
| Initiative | Reactions |
| 0–4 | 1 |
| 5–8 | 2 |
| 9–12 | 3 |
| 13+ | 4 |
[h=4]Point Defence[/h] Turret lasers can be used to destroy incoming missiles. The missiles can only be destroyed in the moments before they strike the spacecraft as they are too small and fast-moving to effectively target at greater ranges. The gunner must make a Gunner (turrets) check against the missile. If successful, the missile is destroyed. A gunner may keep making Gunner checks against missiles until he misses an attack; each attack suffers a cumulative –1 penalty. Attacks may be directed against different incoming missiles.
Point defence can also be used to destroy incoming boarders in the same way.
[h=4]Fire Sand[/h] Turrets equipped with sandcasters can fire sand at incoming beam attacks. Each reaction spent on firing sand allows the gunner to make a Gunner (turrets) roll. If successful the damage of each beam in the incoming attack is reduced by 1d6. Resolve each beam separately. Each firing of sand costs one canister of sand.
Sand can also be directed against incoming boarding parties. If the sand attack is successful, each target in the boarding party takes 8d6 damage.
[h=4]Trigger Screens[/h] Screens can be activated as long as the commander or one of the gunners has the Gunner (screens) skill at Level 0 and the ship has the required screen type (nuclear against nuclear missiles and fusion guns; meson against meson guns). Screens reduce the damage from the attack by 2d6+the operator’s Gunnery (screens) skill. Nuclear dampers also negate radiation hits against crew from nuclear missiles and fusion guns.
[h=2]Ship Action Phase[/h] In each ship action phase, a ship may take one ship action. Ship actions are wholly internal to the ship.
[h=4]Repair Damaged System[/h] A character on damage control may attempt to repair a damaged system by making an Education-based Mechanic check. If the check is successful, determine how many hits are repaired:
| Mechanic Check Effect | Hits Repaired |
| 0 | 1 |
| 1–5 | 2 |
| 6+ | 3 |
These are battlefield repairs only and will break down as soon as the battle is over unless repaired properly.
[h=4]Sensor Lock[/h] A ship’s sensors operator may make an Education-based Sensors check to establish a lock on an enemy vessel. Attacks made against a vessel that has been locked onto gain a +1 DM. When using missiles the initial Gunner check gets this bonus – the individual missile to hit rolls do not benefit directly. Smart missiles are unaffected.
[h=4]Electronic Warfare[/h] A ship’s sensors operator may attempt to jam radio communications and sensor locks by making an opposed Intelligence-based Sensors check against the sensors operator of the opposing vessel. Electronic warfare can be used to break sensor locks.
Alternatively, electronic warfare can be used to attack smart missiles that are targeting the ship. The sensors operator makes a Difficult (–2) Sensors check and, if successful, a single attacking smart missile ceases attacking. The sensors operator may continue making checks to disable smart missiles until he fails one, with a cumulative –1 DM each time.
[h=4]Increase Initiative[/h] The commander of a spacecraft may make a Leadership check and increase the Initiative of his spacecraft by the Effect of the check. This increase only applies for the following round.
[h=4]Change Positions[/h] Any characters not doing anything else may elect to swap positions during the ship action phase. As of the next round they are considered to be manning their new position rather than their previous one.
[h=2]Damage[/h] Systems can take a variable number of hits before being destroyed, depending on the system in question. A ship can endure one Hull damage per fifty tons, rounding down. A ship that runs out of Hull Damage will rapidly be incapacitated. A ship can endure one Structure damage per fifty tons, rounding down to a minimum of one. A ship that runs out of Structure breaks up and is completely destroyed.
The effects of damage are determined by subtracting the ship’s armour from the damage rolled by the weapon, then consulting the damage table to determine the number of hits inflicted. Then roll on the Location table for each hit.
A double hit applies two hits to the same location. A triple hit applies three hits to the same location.
| Damage | Effect |
| 0 or less | No damage |
| 1–4 | Single Hit |
| 5–8 | Two Single Hits |
| 9–12 | Double Hit |
| 12–16 | Three Single Hits |
| 16–20 | Two Single Hits, Double Hit |
| 21–24 | Two Double Hits |
| 24–28 | Triple Hit |
| 29–32 | Triple Hit, Single Hit |
| 33–36 | Triple Hit, Double Hit |
| 37–40 | Triple Hit, Double Hit, Single Hit |
| 41–44 | Two Triple Hits |
| For every extra three points | +1 Single Hit |
| For every extra six points | +1 Double Hit |
Structure: Reduce the ship’s Structure by one. If a ship’s Structure is reduced to 0, the ship is destroyed.
Armour: Reduce the ship’s armour by one. If the ship’s armour is already 0, then this counts as a Hull hit.
Turret: A random turret is hit.
- First Hit: The turret’s tracking mechanism is damaged. It can still be used, but all attacks suffer a –2 DM.
- Second Hit: The turret and all weapons in it are disabled.
- Third Hit: The turret and all weapons in it are destroyed.
- Subsequent Hits: Count as Hull hits.
- First Hit: The bay’s targeting mechanism is damaged. It can still be used, but all attacks suffer a –2 DM.
- Second Hit: The bay weapon is disabled.
- Third Hit: The bay weapon is destroyed.
- Subsequent Hits: Count as Structure hits.
- First Hit: All attempts at Jump suffer a –2 DM to Engineering (jump) checks.
- Second Hit: The jump drive is disabled.
- Third Hit: The jump drive is destroyed.
- Subsequent Hits: Count as Structure hits.
- First Hit: Reduce the ship’s thrust by one.
- Second Hit: Reduce the ship’s thrust by 50%.
- Third Hit: The drive is disabled.
- Subsequent Hits: Count as Hull hits.
- First Hit: Damaged.
- Second Hit: The crew suffer a Crew Hit, rolling on the Radiation Damage column.
- Third Hit: The Power Plant is destroyed and the ship is disabled.
- Subsequent Hits: Count as Structure Hits.
- First Hit: –2 DM to all Sensors checks.
- Second Hit: Sensors are disabled preventing the ship from making Sensors checks and on making attacks on targets beyond Adjacent range.
- Third Hit: Sensors are destroyed.
- Subsequent Hits: Count as Hull hits.
- First Hit: The crew suffer a Crew Hit, rolling on the Normal Damage column.
- Second Hit: The bridge is disabled. Until the bridge is repaired, the ship cannot take any Pilot or Sensor actions, it cannot jump, and any attacks suffer a –2 DM.
- Third Hit: The bridge is destroyed.
- Subsequent Hits: Count as Structure Hits.
- First Hit: Causes a minor fuel leak of 1d6 tons per hour.
- Second Hit: Destroys 1d6 x 10% of stored fuel.
- Third Hit: Destroys fuel tank.
- Subsequent Hits: Count as Structure Hits.
- First Hit: Destroys 1d6 x 10% of stored cargo.
- Second Hit: Destroys 1d6 x 10% of stored cargo.
- Third Hit: Destroys cargo hold and everything in it.
- Subsequent Hits: Count as Structure Hits.
| Roll | Normal Damage | Radiation Damage |
| 4 or less | Lucky escape – no damage | Lucky escape – no radiation |
| 5–8 | One random crew member suffers 2d6 damage | One random crew member suffers 2d6 x 10 rads |
| 9–10 | One random crew member suffers 4d6 damage | One random crew member suffers 4d6 x 10 rads |
| 11 | All crew suffer 2d6 damage | All crew suffer 2d6 x 10 rads |
| 12 | All crew suffer 4d6 damage | All crew suffer 4d6 x 10 rads |
[HI][trav]Mongoose Traveller SRD[/trav][/HI]
