The stats I have are:
Warhead Strength: 5
Engine Power: 3
Agility: 64
Efficiency: 0.8
OK, I've set up a dummy game with those techs, and I can walk you through the process of creating a size-1 AMM (anti-missile missile) and a size-6 ASM (anti-ship missile). You may prefer a smaller size for your ASM... many players like to use size-4 instead of size-6, since it reloads faster and takes up less magazine space... but the same method can be used to create effective missiles of any size.
Size-1 AMMFirst, set your Warhead Strength MSP to whatever value it takes to get a strength-1 bang. At your current tech level, that's 0.2 MSP = strength-1.
Next, set the Agility MSP to zero temporarily, while we adjust the other stats. We will be returning to set the Agility later, but start it off at zero.
Set the Fuel MSP to whatever it takes to give you the desired range. Early in the game, your PD (Point Defense, res-1) Active Sensors won't be able to spot incoming enemy missiles beyond a million or so kilometers anyway, so twice that figure (about 2 m-km) should be plenty of range for an early-game AMM.
Remember that Fuel/Range figures can be misleading if you haven't yet ballasted your missile up to its final weight... if you've only typed in numbers that total 0.5 instead of totalling 1.0, then your range figure will be misleadingly high. Always ballast your missile up to its design weight before making any major decisions.
Now put all of the remaining points (to bring your missile up to a total weight of 1.0000) into Engine. Check the Fuel/Range again, and make any needed adjustments. It should look something like this, at this point in the process:
Notice that the missile mass totals 1.0000 and that the to-Hit vs 10,000 kps targets is only 47.4%. Not very good, since nearly all missiles will be moving faster than that.
Now we transfer some of the points from Engine to Agility, to improve that to-Hit percentage. Recall the formula that I posted in my Kiwi/Emu Missile Design thread:
These MSP should first be distributed as follows:
If S = the missile size,
and M = your current missile agility per MSP (depends on tech),
and T = the total MSP available for Engines plus Agility,
Then E = (T/2)+(5xS/M) is the amount of MSP that should be used for Engines
and A = (T/2)-(5xS/M) is the remaining MSP that should be used for Agility.
These numbers should then be adjusted up or down so that your actual missile agility is a whole number... ideally, a whole number that is an even multiple of your missile size.
Since we've temporarily zeroed-out the Agility, the number in the Engine box is our T variable for that equation. S is the missile size 1, M is your Agility tech, 64.
So E = (T/2)+(5xS/M) = 0.79/2 + (5x1)/64 = 0.4731 (rounded to four decimal places, which is all the game uses)
Put that number in the engine box, and put all the rest of your points... enough to bring the missile mass back up to 1.0000... into Agility. Now your missile design looks like this:
Your to-Hit has improved from 47.4% to 85.2%! We're not quite done yet, though. Notice that your Agility MSP (0.3169) gives you an Agility value of 20.2816... this number really should be an Integer multiple of your missile size... with a size-1 missile, any Integer will do. So we slightly adjust the Agility MSP to drop the Agility Value down to the nearest whole number, 20:
... and that slightly improves our to-Hit once more, to 85.8. NOW we're done. Name it, save it, research it and build it.
For your size-6 ASM, the same steps apply. I've chosen a strength-4 warhead (it should usually be a perfect square such as 1, 4, 9, 16 etc, for best armor penetration), and a range of 60 m-km.
The process is exactly the same... first set the warhead, then set Agility to zero, then set the fuel and ballast the missile up to its design weight (6.0000), then work out the formula and transfer some points from Engine to Agility, lastly reduce the Agility to a whole-number multiple of the missile size, by moving a few fractions of a point back into Engine.
Screen-shots:
