[Varyon]

One important thing to keep in mind is that many of the options that make a distinction between missiles and boarding craft don’t account for the fact that, particularly in space, you can easily make a boarding craft-like missile. Do shields negate each other? Build a shielded missile. Is there a size cutoff? Use missiles that are the same size as the boarding craft. Need better maneuverability? Design the missile to have the same maneuverability as a boarding craft. Do you require a human on board to get past the shield? Someone’s going to come up with kamikaze missiles - or manned missiles that eject their passenger before exploding. Do the shields let only slow-moving objects past? Design missiles to slow down just before impact, and pack them full of explosives. Does the shield fry electronics, as in safisher’s suggestion? Use a mechanical trigger (a clockwork timer that’s normally held “off” by electromagnets would work - when the missile gets EMP’d, the magnets shut down and the timer starts up).

That said, there are options to make boarding craft viable. It should go without saying, but all of these assume attempts to just bombard the ship with attacks until the shield is overwhelmed and the ship is dust aren’t particularly viable.

Culture: Never underestimate this one. Nukes weren’t used in Dune (well, they were, but that’s because Paul’s a filthy cheater), not because some technology had made them technologically nonviable, but because you’d have everyone against you if you used them. Any of the above counters can be negated by Culture - missiles larger than 600 lb (SM+1) are forbidden by interstellar treaties, only a barbarian would use manned missiles, and so forth.

Economics: If the salvo of missiles you need to use to take out an enemy ship costs more than the number of boarding craft and crew lost (as well as resources consumed by those that aren’t lost) taking out the ship trying to go that route, you may end up with boarding craft being preferable. That’s not a highly likely situation - boarding craft are going to have a lower rate of success than missiles, and if they need to be made similarly it’s unlikely the explosive payload costs more than the crew accommodations, gear, and of course the training and pay for the boarders.

Ship of Steel, Missile of Nerf: If there aren’t explosives powerful enough to take out a ship when packed in a boarding craft-sized missile (and kinetic kills aren’t an option), you’ll need a boarding party to get in to take over or sabotage the ship to beat it.

Internal Shields: Shields are usually handled as a shell surrounding the ship, but what if they instead strengthened the ship’s structure and components? That is, instead of granting DR, they granted a high level of IT:DR. If you’ve got a setup where it’s possible to locally negate a small section of shielding (say, with shielding of your own), then a missile can only vaporize a small part of the ship at a time, but a boarding craft can cut a hole in and insert a boarding party to overtake or sabotage the ship. Heck, if you make the shield a field, and go with the option of it letting slow moving things through, you can end up with a case where boarders (and the defenders) have to engage in melee combat, because the shield absorbs their ranged attacks.

Valuable Component: If ships contain some valuable component that the other side could use - rare precursor artifacts, brainwashable psionic operators, whatever - then destroying the ship with missiles may be a bad idea. You’ll want to send in a boarding party to, at the very least, steal the component and get away before the ship gets pounded to dust.


My own space opera setting I’ve been working on combines several of these. Culture is mostly used just for taking nukes - and nuclear energy - off the table. In that, capital ships tend to have two layers of shielding - an external shell, and an internal field. The shell is susceptible to being broken down by other shields, and is of variable reliability - it’s actually wired into the pilot’s brain (typically through something akin to the TL10 Neural Interface Helmet) and uses this to “flicker” the shield (it can’t be maintained) to block attacks. It can’t interact as readily with large or slow-moving objects, and while the flicker can’t be predicted by computers (unless you don’t have it linked to a human brain, but that’s just asking for trouble), a quirk of human pattern recognition means it can be predicted, albeit subconsciously (shows up more as a gut feeling than a proper prediction), by a wired-up human brain. I need to work out the numbers, but basically how it works out is that shields take an Active Defense (in addition to the Dodge of the pilot, if applicable) based on the pilot’s ship operation skill, with penalties for large or slow-moving attacks, while the attacker can take a penalty (which can be reduced by a Technique, unlike Deceptive Attack) to reduce this and give him a better shot at getting through. “Blind fired” (those made without human guidance) attacks have almost no chance of getting through a shield. Gunners can typically only control one missile at a time. The internal field layer on capital ships isn’t nearly as effective as the “shell,” but doesn’t suffer from variable reliability. It will basically leech the energy from energy attacks and explosions, greatly reducing their range.

Combined with the fact that the way the drives work space battles literally take place at ranges and speeds more akin to WWII naval battles (with aircraft carriers), the whole affair means that fighters are susceptible to missiles and other projectiles (beams and bullets, provided the shooter is sufficiently skilled to get past the shield). Capital ships are typically large enough, and their internal field strong enough, that beams, bullets, and explosions (from missiles) are typically only able to damage the outer structures in the short term, although with enough damage and enough passage of time the external shell will overheat and have to be shut down, which will render the capital ship more susceptible to external threats. If fighting it long enough to take down the external shell isn’t viable, boarding parties can get in to sabotage the ship. Mecha make for another complication (they have blades functionally made of collapsed shielding, which do more damage to capital ships than they really have any right to), but that’s the basics of it.