For the most part, spacecraft attributes represent the same things for spacecraft that they do for spaceships, as defined in the Cortex and Serenity rules. Differences in this revision are noted below. Values above d12 are usually limited to highly advanced, rare spacecraft.
Armor - Any spacecraft expected to take fire will have armor. The armor will usually be heavy enough to withstand the middle range of damage from the most likely weapon fired at it. Armored fighting spacecraft will usually have enough armor to withstand a hit (50%) from their main weapon.
Weapons - Most weapons are treated essentially like larger versions of personal weapons, with a damage, range increment, and ROF. All normal rules apply.
Missiles - Missiles are a special case, and come in three varieties: unguided, guided, and homing.
Unguided missiles are simply called rockets, and are the cheapest sort available. They are targeted using the firer’s Agility + Heavy Weapons (Missile) skill as per standard ranged attacks. If they miss, they are lost.
Guided missiles are steered towards the target by the firer, and rely on the missile’s Agility + the firer’s Heavy Weapons (Missile) skill. If they miss, they can be guided in for one more attack at a -2 step penalty.
Homing missiles use their own Agility + Heavy Weapons (Missile) skill, and can make up to three attack runs before running out of fuel. They use this same skill roll as a Dodge roll against point defense fire.
Anti-Missile Defenses - All three types of missile are vulnerable to point defense fire, while guided and homing missiles are vulnerable to ECM.
Point Defense requires a weapon capable of automatic fire, and must target each missile. The defender must make an Agility + Heavy Weapons skill roll, beating a Average (7) roll to hit an incoming unguided rocket, a Hard (11) to hit a guided missile, and an Agility + Heavy Weapons (Missile) roll as a dodge by a homing missile. Any hit will destroy the incoming missile.
ECM requires a functioning ECM rig, and an operator to make an Intelligence + Technical Engineering (ECM) roll versus Intelligence + Heavy Weapons (Missile) for a guided missile, or Agility + Heavy Weapons (Missile) for a homing missile. Success will turn the oncoming missile aside for the turn.
Armor Piercing Ammunition - Due to the effectiveness of armor, many combat spacecraft use various sorts of armor-piercing ammunition, whether hypervelocity kinetic-kill rounds, or massive shaped-charge warheads. All of these can be generalized. Reduce the effective armor value by ½, and then whatever damage penetrates is also reduced by ½.
Damage to Spacecraft - Most spacecraft don’t have a lot of empty space inside their hulls, cargo space notwithstanding, so any hit which breaches the armor is likely to damage something important. Vehicles have structural points equal to Vitality + Willpower + (Strength x 2), so a typical frigate of Strength d8, Vitality d8 and Willpower d8 would have 32 structural points. Performance is quickly eroded as damage accrues.
On any Extraordinary Success which manages to penetrate armor, the spacecraft takes more severe damage. In each case, the spacecraft must roll Vitality + Willpower versus the amount of damage penetrating armor to avoid the listed effect. Each result leaves the spacecraft vulnerable to additional damage.