Missiles in Mongoose Traveller
This document replaces all missile rules for MGT, except where stated otherwise.
Missile Sizes
There are four sizes of missile: antimissile, light, heavy and torpedo. (NOTE: I'm thinking of changing this to simply "light, medium, heavy, and torpedo" as I think antimissile gives the wrong impression.)
Light missiles are the current standard missiles, at 12 per dton.
Medium missiles are twice the volume, fitting 6 per dton.
Heavy missiles are twice the volume again, at 3 per dton.
Torpedoes are also called capital missiles and take up 2.5 dtons each.
The missile size determines the basic capabilities of the missile, including acceleration, endurance, and warhead size. Certain types of modifications are allowed, such as extended range, enhanced acceleration, etc.
All missiles are assumed to have basic command guidance. Guidance systems can be upgraded, primarily at additional expense.
Missiles past antimissiles are armored to resist damage. Any hit destroys the missile, but only if the damage exceeds the armor.
Missile chassis are listed in Table M1: Missile Size.
Type Acceleration Endurance Armor
Antimissile 15G 10 turns 0
Light 10G 10 turns 2
Heavy 8G 10 turns 3
Torpedo 8G 10 turns 4
Warheads
Warheads are rated by size, as above.
Most warheads are available in all four sizes, but obviously have different capabilities depending on size.
Available warheads are listed in the following table.
Table M2: Warheads
Type TL Light Medium Heavy Torpedo
HEAT 7 1d6 AP 2d6 AP 3d6 AP 4d6 AP
Nuclear 7 2d6+2xE+CH 4d6+4xE+CH 8d6+8xE+CH 16d6+16xE+CH
X-ray Laser 9 1d6 AP 3d6 AP 6d6 AP 12d6 AP
Plasma 12 1d6+1 Super-AP 2d6+2 Super-AP 3d6+3 Super-AP 4d6+4 Super-AP
Ortillery 7
Shockwave 7 Special N/A N/A N/A
All references to armor piercing ability reference the Central Supply Catalog.
HEAT Warheads are High Explosive Anti-Tank (or Armor-Tapping). They are the standard warhead and use a shaped charge to create a jet of pencil thin molten metal that can penetrate armor. Effect adds to damage normally and they ignore their full dice of damage in armor.
Nuclear Warheads are fission or fusion devices built at arbitrary yields depending on the size of the warhead. Because nuclear weapons are incredibly deadly at close range (or contact), the damage from Effect is modified as per the table above. A heavy nuclear missile can destroy a small spaceship in one hit (using my modified damage rules). These yields are not the only possible yields, but represent reasonably sized warheads. All of them would cause significant damage in an atmosphere and such use would violate Imperial High Law. All nuclear weapons inflict a radiation crew hit as well. Nuclear dampers behave differently than the standard rules: the first nuclear damper defeats the crew radiation hit. Each subsequent nuclear damper halves the damage of the weapon (so five nuclear dampers effectively eliminates nuke warheads as threats).
X-ray Laser (or detonation laser) warheads use a nuclear warhead to generate powerful X-ray laser strikes. Because they detonate well clear of a target, point defense is less effective. Sandcasters may be used to defend against the laser, but not to shoot down the missile. Lasers used as point defense are fired with a -2 DM. X-ray laser warheads are Armor Piercing. X-ray laserheads are not subject to nuclear damping because they detonate beyond the field effect.
Plasma (actually directed plasma) warheads an advanced form of HEAT warhead available at TL12. Effect adds to damage normally but they receive twice the normal armor piercing effect and receive a slight damage bonus.
Ortillery warheads are not used in space combat, but are used to bombard troops and fortifications from space.
Shockwave warheads are available only as light missile warheads and are used to disrupt enemy sandclouds as per High Guard.
Missile TL Upgrades
In addition to the standard upgrades for weapons (Accurate, High Yield, etc), missiles can have improved engine systems. Two upgrades are available: Boosted and High Endurance. Boosted missiles use 1 or 2 upgrade slots at +1 or +2 TLs and increase Acceleration by 25% and 50% respectively. High Endurance upgrade uses up 1 upgrade slot and increases Endurance by 25%.
Missile Options
The following missile options are available for all missile types.
Long Range: Increase Acceleration by 50%, decrease Endurance by 30%.
Multi-Warhead: Decrease Acceleration by 20%, fits 6 warheads of two sizes lower, and 1d6 hit.
Smart Guidance System: This modification allows the missile to direct itself. A smart missile or torpedo can be created at TL8. Such missiles will hit on an 8+ and can make attacks until their Endurance is exhausted or until they are shot down. At TL10, brilliant missiles replace smart missiles and receive a +2 DM to hit. At TL12, genius missiles replace brilliant missiles, and receive a +4 DM to hit.
Launch Systems
The basic launch systems are turrets, barbettes, bays, and heavy bays.
There are two types of turret-mounted missile launchers: standard and large. The standard missile launcher may fire 1 light or medium missile per turn and takes up 1 turret space as per MGT Core. The large missile launcher may fire 1 heavy missile per turn and takes up 2 turret spaces as per my house rules (alternately, they are treated like particle beams, and only can be fitted per turret, but this requires a triple turret).
A missile barbette can fire 3 heavy missiles per turn or launch 1 torpedo per turn.
A missile bay can fire a flight of 12 light or medium missiles or a salvo of 8 heavy missiles. A heavy missile bay can fire a flight of 24 light or medium missiles or a salvo of 16 heavy missiles.
A torpedo bay can fire 3 torpedoes per turn. A heavy torpedo bay can fire 6 torpedoes per turn.
