Missile Combat

Missile combat is very similar to melee combat, but is distinct in several ways. This system can be used for anything from a thrown rock to a bullet to a space-based laser, and it should actually be possible to play golf, baseball, tennis and so on with these rules. Anything which fires a projectile is generally a missile weapon.

Rate of Fire

Missile weapons have greatly varying rates of fire (RoF), from the very slow (early cannons and muskets) to the very fast (continuous laser beams) and everywhere in between. Each weapon description (see the Equipment chapter) gives a rate of fire, either in jiffies per missile fired (for slow weapons, such as bows), or missiles per jiffy (for fast weapons, such as fully automatic guns). (We generally use the term "missiles" instead of "rounds", as a round is used elsewhere as a measure of time.) The weapon descriptions also give information on the flight speed of the missile (generally in metres per jiffy).

In the case of weapons which take several rounds to fire (i.e. rate of fire is given in jiffies/missile), the given number is the WS, and attacks are handled in much the same way as melee combat.

In the case of weapons which can fire several missiles in a single jiffy, treat the weapon as having a WS of 1, but with multiple chances to hit in a single jiffy. Each missile should be counted as a separate attack, so there will be several to-hit rolls, and possibly several damage rolls. The weapon description will indicate to what extent it is possible to fire at different targets in a single jiffy with the weapon, and what modifiers may be applicable for sustained bursts.

Defending

The target of a missile attack may make a defense roll, if the GM determines that it is possible, and if the target chooses to. The target may not be given a defense roll for many reasons (surprised, too close to the attacker, busy with another action, tied down, already dead, inanimate object, ...). The target must make a defense roll for each incoming missile (including those that would otherwise miss; a critical failure might indicate that the character dodged into the path of the missile).

A defense roll is a reaction to the action of the missile being fired, and so happens in the jiffy following the firing; if the missiles arrive before that time, no defense roll is possible. This is often true for bullets, and always for lasers (since the "missile" is travelling at the speed of light, the target can't tell where it's headed until it arrives). Pre-emptive dodges may take place, based on the aim of the shooter, but these are not defense rolls; rather, they are separate actions, which the shooter can react to in turn.

Which attribute or skill the defense roll is made against will depend largely on the circumstances. A person will make their defense roll against their maneuverability rating (see the section on Movement in Other Rules); a jet fighter pilot would roll against his piloting skill. In case of confusion, the applicable attribute or skill should be determined by the GM (and make a note of the situation and solution, in case it happens again).

Ranges, Damage, etc.

All other information you need will be given in the description of the weapon.

Modifiers

There may be modifiers applied to missile attack rolls, depending on the circumstances.

• Any cover the target happens to have that would stop the missile is ignored when making the attack roll. Instead, determine the hit location; if that area is protected by the cover, the missile is blocked and does not hit the target. If there is softer cover which could block the missile (bushes, for example), the GM might assign a modifier depending of the cover, or might allow the attack as above, and make a separate roll to determine whether the missile was blocked.
• A breeze, particularly a cross-wind, will reduce the chances of hitting. The modifier for this should continually decrease with the second and subsequent shots, as the character gets a feel for what the wind is doing.
• A negative modifier may be applied if the target or attacker is moving in relation to each other (keep in mind that two vehicles travelling at the same speed in the same direction are not moving in relation to each other). If you are really interested in getting this right, consult a physics textbook, especially the sections on velocity and vector addition.
• If the attacker has some sort of targeting system (a telescopic sight on an assault rifle, or a computer controlled tracking system on a missile), the chance of hitting the target go up. This generally only applies to the first missile fired in a round. Details will be listed in the description of the weapon.
• A special case of the previous modifier is simply taking time to aim carefully. For every jiffy dedicated to aiming at an intended target (which target must be specified), the chance of hitting (after all other modifiers are taken into account) is increased by 5% of the modified skill level, to a maximum increase of 50%. This is always applied only to the first shot fired; the second and subsequent shots do not have this bonus. It is generally possible to aim at a moving target; this involves tracking the motion and determining where the target will be by the time the missile arrives. Erratically moving targets (evasive maneuvers!) may not be aimed at, at the GMs discretion.

A sniper has a rifle. His chance of hitting is normally 60. There is a telescopic sight on the rifle which raises his chance to 80. The GM rules that due to the distance, and the facts the target is moving and the sniper has to shoot through a plate glass window, there is a -30 modifier, bringing his chance down to 50. If he were to aim for one second (two jiffies), his chance of success would be increased by 10%(=5%x2) to 55(=50+50x10%=50+50x.1=50+5). If he were to aim for five seconds, his chance would be increased by 50% (the maximum) to 75(=50+50x.5 or 50x1.5).