That is correct. However, the sizes of the two weapons matter not at all, and a quad laser cannon counts as a single weapon system:

Replacing a light laser cannon with a medium laser cannon = no HP.

Replacing a twin medium laser cannon with a twin light laser cannon = 1 HP. (The same as keeping the twin medium laser cannon and simply adding the twin light laser cannon as an additional weapon).

Replacing a twin medium laser cannon with a quad laser cannon = 0 HP.

Just to clarify something, if I wanted to add 4 proton torpedo pods to a ship a la TIE-IT/Punisher with it Linked 3 torpedoes of doom, it would cost... 4HP... right?

On 2/27/2018 at 3:48 PM, Mefyrx said:

So the only way replacing a weapon will cost 0 HP is if the weapon bought is Linked 0 (in other word not linked) and replacing an existing weapon

Not quite true - the quad laser cannon counts as a single weapon, and thus would cost 0 hard points if you replace an existing weapon with one.

1 hour ago, DJCrazee said:

Just to clarify something, if I wanted to add 4 proton torpedo pods to a ship a la TIE-IT/Punisher with it Linked 3 torpedoes of doom, it would cost... 4HP... right?

If it's Linked 3, it counts as one weapon, so 1 HP. As far as I know, anyways.

I could have sworn I read somewhere that you had to pay 1 HP for the initial weapon, plus 1 HP per each "rank" of Linked but I'm not sure and that might just be me remembering falsely.

If it's only 1 HP for the 4 torpedo Linked(3) system, I'm about to be a very happy man.

I was going off memory, but I checked EotE to be sure. Here's what Upgraded Weapons says:

"Hard Points Required: 0 if replacing an existing weapon system. 1 if adding new weapon system. Weapon systems combining two or more weapons always cost one hard point, even if replacing an existing weapon system."

So four proton torpedo launchers is "two or more", so it costs 1 HP no matter what (which means you probably want to add it as a new weapon, not replacing an existing weapon).

A quad laser is one weapon system, though, so it can replace an existing weapon for 0 HP. Four linked light laser cannons would cost 1 HP, no matter what, but they aren't quite the same as a quad laser (no Accurate 1, can be added to a silhouette 3 ship).

Does having a Turret automatically means that it requires a gunner, I would believe so, but just need confirmation