I just got Mask of the Pirate Queen and I'm just wondering why the weapons loadout on the Interceptor-IV class Frigate is so light compared to that of the stock Interceptor-class Frigate.

The Interceptor class has six turbolasers and three proton torpedo tubes while the Interceptor-IV only has 2 turbolasers and one missile launcher. While the lore mentions that the armor is weakened in the upgrades nothing says the armament was reduced just that the torpedo tubes being swapped for missile launchers.

It looks like the writer copied the weapons loadout from the game exactly but that hasn't been done with other designs converted from Forces of Corruption to the RPG so why do it with this one class?

Maybe it's intended to be a light corvette, or a pirating vessel. Something quick enough and armed enough to catch or disable competing smugglers but cheap enough to maximize profits?

I haven't gotten my hands on Mask of the Pirate Queen yet, but assuming this is a ship run by either Zann or pirates, they probably aren't getting them fresh off the dock; they're stealing them, or buying up decommissioned ones, or otherwise acquiring them under the table. So it would make sense that the armament would reflect that status. They're grabbing the ships, probably in banged-up shape, and loading them with whatever weapons they have on hand that will fit into the existing structure of the ship or require minimal retrofitting.

Both classes are modified Action Vi bulk freighters actually but both classes seem to be fairly standardized rather then custom one of a kind jobs like the Wilde Karrde. Forces of Corruption even talks about the kinds of modifications made to convert the Interceptor-I frigates into Interceptor-IVs. It talks about the armor being reduced for more speed but better shielding being equipped. Nothing claims that the numbers of weapons are reduced until now.

Like I said what they did was give it the exact weapons loadout it had in Forces of Corruption but one of the key rules of converting ships between Star Wars computer game rule systems and Star Wars RPG systems is that the games rarely get capital ship weapon loadouts right and the strategy games never do. Some ships like the CR90s the strategy games give completely different loadouts like both Rebellion and Empire at War giving the CR90 exclusively Laser loadouts with no Turbolasers while others get the same types of weapons but increase the numbers from those in the PC games, and some ship classes have the amount of some weapons increased but not others. The Interceptor-Is appeared in a novel which included an exact weapons loadout with each weapon hardpoint in Empire at war representing 3 weapons of the appropriate type IMO it makes no sense for a successor design on the same basic hullframe to only have less then one third the firepower of the original design. In fact the description of the Interceptor-IVs says their weaponry was improved but even if the Interceptor-I's turbolasers were all lights that would be 54 damage output per salvo compared to an Interceptor-IVs 22 per salvo And the missile to torpedo comparison is even worse with the Interceptor-IV inflicting 6 points of damage per salvo while each of an Interceptor-I's tubes would inflict 8 per shot with a total of 24 per salvo.

These ships are supposed to be strong against both CR-90s and Nebulon-Bs but while individually each of the Interceptor-IV's two heavy turbolasers inflict more damage then any one weapon either the Neb-B or CR-90 has both the CR-90 ad the Neb-B have much higher total outputs. Combined an Interceptor-IV can inflict 28 points of damage per salvo with each of the three shots having Breach 4 for a combined Breach 12. CR-90s put out either 56 or 58 damage with each of the six shots having breach 2 or 3 for total Breach of either 14 or 16 and each weapon also has Linked 1 while a Nebulon-B puts out 120 damage with each shot having Breach 3 for a combined Breach 36.

I know the Interceptir-Is do have some edges but with the shortage of raw firepower compared to its predecessor I don't see how the ship we got fits the description from the design's original source.

Game balance.

Fitting the given data is more important. There are plenty of other ways to balance ships without gutting their abilities. And don't tell me a sil 5 ship is limited to 3 weapons because I can provide tons of examples that prove that wrong.

And if the data for a ship class doesn't fit what you need ok but rather then disrespect the work of those who created the original information either take the time to figure out how to make it work (Adjusting the cost works well over all and adjusting the opposing force will work in the event you are using it for a specific battle) or use another ship that fits your needs better, or create a new one if no existing one fits your needs.)

Edit: Also the more I look at the ship's official stats the worse they become. If you could concentrate the fire of both turbolasers in one arc and control the range you might be able to fight a Corvette effectively but the arcs only allow the turbolasers to fire into single arcs so you can't fire both at a single target. Also there are no weapons covering the aft arc.