Aurora 4x

C# Aurora => General Discussion => Topic started by: Arwyn on December 18, 2023, 03:45:27 PM

Title: Quick question on Decoys
Post by: Arwyn on December 18, 2023, 03:45:27 PM
So, I am eagerly firing up a new game to test out all the new goodies, but had a quick question on anti-missile decoys. I get the building mechanics, but I would assume that the decoy signature should be roughly the same as the launching ship, should it not?

Reason for the ask is a couple of autobuilt designs are 16k tons and have decoys with 8k signature strength, which seems wrong. But I thought I would ask as I may be missing something. :)
Title: Re: Quick question on Decoys
Post by: Snoman314 on December 18, 2023, 03:53:36 PM
Well, you want large decoys. But the optimal size probably depends more on your CIWS situation. There was more discussion on this a while back, but I find I've forgotten most of it: http://aurora2.pentarch.org/index.php?topic=13098.msg164901#msg164901 (http://aurora2.pentarch.org/index.php?topic=13098.msg164901#msg164901)
Title: Re: Quick question on Decoys
Post by: Droll on December 18, 2023, 03:53:55 PM
So, I am eagerly firing up a new game to test out all the new goodies, but had a quick question on anti-missile decoys. I get the building mechanics, but I would assume that the decoy signature should be roughly the same as the launching ship, should it not?

Reason for the ask is a couple of autobuilt designs are 16k tons and have decoys with 8k signature strength, which seems wrong. But I thought I would ask as I may be missing something. :)

The chance of an incoming missile getting fooled by a decoy is proportional to the ratio of total launched decoy signature vs ship tonnage. The full formula is somewhere in the 2.3.0 changelogs I think.

If you have a 16k ton ship that launches a single 8k decoy, the chance of a missile instead going for a decoy is 8,000 / (8,000 + 16,000) = 33% chance the missile attacks the decoy instead.

Note that you can launch multiple decoys, so in the above scenario if the ship were to launch 2 decoys it would be (8,000 x 2) / ((8,000 x 2)+ 16,000) = 50% chance the missile attacks a decoy instead. This is why the signature of the decoy is less than the ships, it doesn't need to be equal for it to have a significant effect.

Finally, the above assumes that there is no ECM advantage vs the missiles ECCM. An ECM advantage acts as a multiplier on the decoy's signature, IIRC an ECM advantage of 5 would double the effective signature of the decoy and an ECCM advantage of 5 will make the missiles completely ignore the decoys.
Title: Re: Quick question on Decoys
Post by: Ulzgoroth on December 18, 2023, 03:55:19 PM
It's not required that the decoy signature matches the ship signature - you might want it the signature to be less or conceivably even more than the ship's size.

Decoy mechanics post here (http://aurora2.pentarch.org/index.php?topic=13090.msg164759#msg164759).
Title: Re: Quick question on Decoys
Post by: Arwyn on December 18, 2023, 04:09:43 PM
Exactly what I was after, thank you all and thanks for the link. I searched earlier, but just kept getting Steve's inital post.