I have come across this oddity quite a while ago and do not have a saved game to show this. But I have seen the Psilons as an AI putting 2 Inertial Stabilizers on the same ship. When I design ships as a human player I cannot do this.
When seeing this I thouhgt: "Oh, this is quite neat! Wanna do something like that myself!" But found out the human player cannot do it.
I wasn't thinking about Inertial Stabilizers when doubling special equipment though. What I had in mind was doubling Automated Repair System. When you look at the cost and the size of ARS compared to Advanced Damage Control you can see that two ARS take up less space than one ADC and even cost less. So it sounded like an interesting option but only the AI can do it.
I think the human player can put one ARS plus one ADC on the same ship. Not sure - haven't tried that yet. Should repair 45 % of the hitpoints per turn (2 ADCs would repair 60 % per turn).
Not that the advantage given to the AI here is really huge or decisive. There are ways out for the human player to achieve almost the same by combining two different special items. Even if they can double certain items they still only have 3 slots for special items. And doubling one item costs one slot that is not available for something else. Also costs ship space and BC.
For instance if you use inertial stabilizer plus battle scanner you also get a somewhat greater speed advantage than with using just one IS only.
Interesting combination would be having two lightning shields on a bomber. But in that case a human player could combine one zyro shield with one lightning shield and achieve almost the same. Not that I would really do it. Instead of another powerful shield I would pack more bombs on that ship - or combine IS with Lightning Shield to get the bomber to the enemy bases faster.
Cloaking Device plus IS would give you almost as much of a defence bonus as two Cloaking Devices. But Inertial Nullifier might be more effective than Cloaking Device - since you don't lose the bonus when firing. On the other hand two IS take up less space and cost less than one IN. Only for the AI again - since the human player cannot do it.
Two Reserve Fueltanks on the same ship would be wonderful!! Haven't seen the AI doing this either. May not be possible even for them.
Not all special equipment items do offer extra bonus when being doubled. Having two colony bases on the same ship is rather useless. The higher one decides what you can colonize. And there seems to be a bug that sometimes AI colony ships don't get used up when they colonize a planet anyways (note: I actually think this is due to the same programming mistakes that cause the negative fleet bug). So they would not profit from having another colony base on the same ship. By the way: The reverse bug also seems to exist: AI Colony ship disappearing without the planet being colonized! I have seen that one myself. And they did not scrap the colony ship - since other colony ships of the same type they had were still there. There were other ships in that particular stack when that happened. The other ships were still there after that - only the colony ship was gone but the planet was not theirs. And that was a game where they got the negative fleet bug over and over again.
I have only seen them doubling special items with Inertial Stabilizers. I don't know whether they can even do it with anything else.
It's not decisive for gameplay. I just thought this was an oddity worth sharing.
When seeing this I thouhgt: "Oh, this is quite neat! Wanna do something like that myself!" But found out the human player cannot do it.
I wasn't thinking about Inertial Stabilizers when doubling special equipment though. What I had in mind was doubling Automated Repair System. When you look at the cost and the size of ARS compared to Advanced Damage Control you can see that two ARS take up less space than one ADC and even cost less. So it sounded like an interesting option but only the AI can do it.
I think the human player can put one ARS plus one ADC on the same ship. Not sure - haven't tried that yet. Should repair 45 % of the hitpoints per turn (2 ADCs would repair 60 % per turn).
Not that the advantage given to the AI here is really huge or decisive. There are ways out for the human player to achieve almost the same by combining two different special items. Even if they can double certain items they still only have 3 slots for special items. And doubling one item costs one slot that is not available for something else. Also costs ship space and BC.
For instance if you use inertial stabilizer plus battle scanner you also get a somewhat greater speed advantage than with using just one IS only.
Interesting combination would be having two lightning shields on a bomber. But in that case a human player could combine one zyro shield with one lightning shield and achieve almost the same. Not that I would really do it. Instead of another powerful shield I would pack more bombs on that ship - or combine IS with Lightning Shield to get the bomber to the enemy bases faster.
Cloaking Device plus IS would give you almost as much of a defence bonus as two Cloaking Devices. But Inertial Nullifier might be more effective than Cloaking Device - since you don't lose the bonus when firing. On the other hand two IS take up less space and cost less than one IN. Only for the AI again - since the human player cannot do it.
Two Reserve Fueltanks on the same ship would be wonderful!! Haven't seen the AI doing this either. May not be possible even for them.
Not all special equipment items do offer extra bonus when being doubled. Having two colony bases on the same ship is rather useless. The higher one decides what you can colonize. And there seems to be a bug that sometimes AI colony ships don't get used up when they colonize a planet anyways (note: I actually think this is due to the same programming mistakes that cause the negative fleet bug). So they would not profit from having another colony base on the same ship. By the way: The reverse bug also seems to exist: AI Colony ship disappearing without the planet being colonized! I have seen that one myself. And they did not scrap the colony ship - since other colony ships of the same type they had were still there. There were other ships in that particular stack when that happened. The other ships were still there after that - only the colony ship was gone but the planet was not theirs. And that was a game where they got the negative fleet bug over and over again.
I have only seen them doubling special items with Inertial Stabilizers. I don't know whether they can even do it with anything else.
It's not decisive for gameplay. I just thought this was an oddity worth sharing.
