Missiles have a lot of utility in the game Master of Orion.
Torpedoes have a lot in common with missiles so they will fall under this heading as well. There really isn't a lot of difference in how you use them and they really aren't even that particularly good most of the time, but feel free to just consider them to be the same as missiles. Chances are you won't get them till you have already won anyway as torpedoes are usually only available relatively late and not even gotten as soon as they are available.
The best things about missile racks are that they (1) can fire every turn till they run out of ammo, (2) allow you to attack enemies without being close to them, and (3) they do consistent damage.
These benefits combine to make missiles potent weapons that are pretty useful for hit and run attacks.
It is helpful to move first if you are making a hit and run missile ship. You will want the best engine possible, the best maneuverability possible, and the best targeting computer possible. Unless your enemies are massively ahead of you in technology this should ensure that you go first every time. It is also most useful to use this strategy early in the game before enemies start loading up their ships with ECM jammers and before advanced planetary defense shields are constructed.
There is no real need to put an ECM on your own ships nor any advanced hull armor nor any special systems on the ships you are doing this with. The key thing here is redundancy. You want to only focus on 3 things (1) making sure you go first, (2) moving up and firing, (3) retreating.
If you do this right, you should be able to hit their planet with a shot of missiles and then retreat without getting hit yourself. You can hit their ships this way too if they don't retreat them.
The best racks to use are going to be the 2 shot racks. You will likely be able to fit 3 racks of 2 shots in the same space as 2 racks of 5 shots. The 2x5 would give more shots than the 3x2 configuration, however, if you aren't going to stick around for more than 1 or 2 turns you get no utility out of shots 3 through 5 on the 5 racks and it is just wasted space. You might as well just get 50% more shots on turns 1 and 2.
The quintessential missile boat is an unarmored, unshielded Medium design with strong engines and maneuverability, your best computer, and one or two 2c racks of your best missile. If your tree lacks good engines but does have Inertial Stabilizer, you might want to use that for the extra movement. A developed medium planet with no extra Robotic Controls tech can build 3 or more of these a turn, letting you build a substantial fleet of boats.
Alternately, you can go with a Small hull, but you may be forced to sacrifice computers or maneuverability to fit your best missile. Warp is still something you probably want as high as possible even if you set to minimum maneuverability, as the ability to quickly move your forces to where they are needed remains valuable. This lets you get even more missiles in the air for the same price, but your boats are much flimsier and you need to be even more careful during actual tactical combat. You want to make two Small designs with the same contents instead of one. A single design forces all ships to be in a single large stack, which in actual combat might overkill a single design of your enemies and would have to retreat to reload to kill other designs, whereas two different designs with the same equipment can choose to target two different enemy designs and not have to reload.
There is really not much more to this plan than that.
It is important to note that if you shoot missiles at enemy ships, they will often try to fly backwards toward their original side of the screen. Missiles fired from ships can only fly for 2 turns before they run out of fuel (the missile disapears. A lot of times, flying backwards like this will let them escape being hit, which is their goal anyway.
This is partially why you want to target the planets first. The planets don't fly away, they have no choice but to sit there and get hit. A second reason is that the planets shoot missiles at you. If you are trying to kill their ships with these missile ships, it will be mandatory to first kill their planetary missile bases so they don't kill you first.
Once the planetary missile bases are gone, a lot of times you can do the same plan as before, but just move up farther so you can be within 2 turns of missile flight from the edge of the screen of the enemy.
This is hard to get right, but it can / does work if you try hard enough. It is even possible to win with no higher than Merculites or Stingers, if you add a few Autorepair Huge "tank" designs to support your swarms of missile boats and aggressively invade before your opponents can tech up to higher ECM or Zyro or Lightning shields. Use the huges to hold a defensive line over newly-captured worlds while your missile boats move on to the next target, then send over a new Huge with the invasion transports for the next target, then repeat.
This plan probably isn't worth doing most of the time and is only really worth doing if you have randomly gotten a lot of good missiles in your weapon technology tree and not much else of use. It is hard to pull off and perhaps a bit annoying to try to do, but it does allow for that elusive gameplay experience where you are able to kill their ships in large numbers and never lose any yourself.
That last part is why it is done, that is the holy grail of Master of Orion combat and the only way to achieve it early in the game at all.
There are two more important things you can do with missiles. One is for defensive fighting, and the other is for what some game cultures might call "crowd control".
Defensive Fighting If you load up one copy of your worst missile onto every ship you make, you can turn it off in combat at the bottom of the screen and allow yourself to move after you have fired all of your other weapons. This is a good thing to be able to do. Maneuverability is very important in this game. This only really applies in defensive combat, though, because offensively you would be better off just putting bombs on your ship instead. You don't have to turn bombs off to do the same thing and you might actually want to use the bombs at some point rather than having a weapon that is low enough in damage not to be able to hurt anything anyway.
Crowd Control As for the "crowd control" ability of missiles, it is surprisingly good. You can aim a rack of missiles at a target that you want to run away from you and often it will. This allows you to separate out some targets and make them retreat while the others continue to advance.
If they have 2 ship designs, one of which you would just flat out own and the other of which would cause you some massive problems, often you can aim the missiles at the powerful one and then blow away the weak ones. After that is over the powerful ones will come forward and you can just retreat. This might also let you kill a lot of enemy ships and lose none of your own.
If you have multiple ship designs, it gets even worse. If you have 2 designs on the board and they have 3, you can make 2 of them withdraw to the edge of the screen and only one advance. This turns a 3 on 2 into a 2 on 1 going the other direction. This is very worth doing if you can pull it off, but generally you won't be able to do it with weak missiles.
For both the hit and run ship with all missiles and the crowd control ship you will want to always use the best missiles you can get. For the maneuverability benefit, always use the worst kind you have to save the most space for other stuff that is useful for actually winning.
That is really about all there is to it.
Missile bases will always upgrade themselves to the best missile as priority number 2 after building a planetary defense shield and this is a good thing. The math works out so that better missiles across all your old bases generally pays off more than leaving worse missiles on old bases and building new bases with the best missiles. The designers saw this and coded it the intelligent way, thankfully.
You will want to research new missiles all the time anyway just to have the best planetary defenses you can, so feel free to try using the hit and run ships and the crowd control ships sometime. Missiles tend to do very well against ships for most of the game due to the fact that missiles tend to do about three times the damage of the equivalent level ship deflector shields.
Assuming you research both missiles and shields as early as you can, the following is true:
- You start the game with 4 damage missiles and only class 1 shields.
- When you get 6 damage missiles, you only have class 2 shields.
- When you get 8 damage missiles, you only have class 2 shields.
- When you get 5 x 6 damage missiles (scatter pack V), you only have class 3 shields.
- When you get 10 damage missiles, you only have class 4 shields.
- When you get 15 damage missiles, you only have class 4 shields.
- When you get 7 x 10 damage missiles, you only have class 6 shields.
- When you get 20 damage missiles, you only have class 6 shields.
- When you get 25 damage missiles, you only have class 9 shields.
- When you get 30 damage missiles, you only have class 11 shields.
The game keeps the ratio between 2 and 4 pretty consistently, though it is lumpy on some occasions. The ratio is never less than two even after class 11 shields turn into class 15 shields with no more powerful missiles possible.
Note, this only counts the absorbed damage portion. Your targeting computer plus your missile's targeting computer versus their maneuverability plus their ECM will still cause your missiles to lose damage from missing. The above only applies to missiles that hit. If they dodge every missile, you still do 0 damage regardless what their shields are. Usually, this isn't a big deal though because for most of the game missiles hit pretty reliably due to the high cost of ECM Jamming equipment in the early game.