APHE is also going to delete a lot of ERA blocks that way. The way you were doing the staggered ERA the first time is optimal (from the logic I'm aware of), with the rear layer against the outside and the outer layer against the inside. Why? Because this does not leave gaps in the ERA that a shell could pass through from an angle. Something I learned could happen from AAS Felix, which I tested myself- ERA blocks literally mesh as half a block when it comes to shell damage. I haven't tested that with applique to see if it's the same, but I did test it with 70* firing angle. Yet, it does also contain an APHE blast to destroying only 2 or 3 ERA blocks rather than 9. A 66%+ better chance over the course of a fight of preventing a deeper penetration from subsequent shells, and a savings of 30+ materials per shell. Though with frag, who knows? This version might be better against APfrag, also. Tradeoffs, tradeoffs. Then again, if you have a specific shell type you know you'll be facing, it's possible to optimize the armor to that shell type, such as this method against HEAT. But going in blind, this version may be good against HEAT, but fails to APHE and APFlak (though not many use the latter presently, the former is in use). Going in blind, staggered is going to present an average of better results against potential shell types, so long as it is sandwiched. Though every armor scheme has its weakness, unavoidably.

What about HESH shells? ERA specifically calls out in the description that it gets instantly deleted without effect if a HESH shockwave hits it, which is something that having the airgap in front prevents by making the shockwave trigger into spalling first.

Of course ERA should have the flat side against the armor if it's in an air gap. The other way (shaped side outward) is for when it's the outermost layer. Think about it from the shell's perspective... a HEAT shell sees, say, a metal block first, so it starts its armor penetrating phase, using up penetration metric as it goes. It does this until it... A) runs out of penetration ability, in which case it fizzles, B) hits not-armor (air or internals), in which case it shifts into its spalling phase and generates fragments, or C) hits an ERA block. It's important to understand that by this, we mean the actual black, solid portion of the block, not "a voxel that contains some ERA somewhere". In this case, the propagating penetration stops, and the round is deleted without generating its fragments. When you have your ERA facing the 'normal' way, in an air-gap (the way the graphics suggest it should be facing, with the flat side against the inner hull and the curved side facing the enemy), what does the HEAT shell see? Let's say we have 2 meters of metal, then a layer of outward-facing ERA on a wood inner hull. For a while, the shell is flying through the air, doing shell things. Then it sees the metal. "Ah, I'm in metal now," it thinks. "I should generate my penetration metric." So it does, and that gets reduced by the first meter, but it's not enough. Now it goes into the second meter of metal. That also subtracts from its pen metric, which is still not enough. What does it see next? Is it ERA? Well, no. There is some ERA in that voxel, but it's at the far end of it. No, what it sees as it exits the metal... is *AIR.* So what does the shell do? "Ah, I'm seeing air, now. That means I get to create my spalls, hooray!" So it creates them. From here on out, these fragments are _exactly like Frag particles,_ i.e. to them, ERA is just an expensive block without much HP, and no special abilities at all. Congratulations; you have successfully used ERA completely incorrectly and utterly misunderstood how HEAT and HESH shells work.

Wow,I didn’t realise but I was using ERA wrong this entire time.

This video had nothing but porn spambot comments, fixed that for you Gmodism! I know FtD isnt a realism simulator, but somehow I can't shake the idea this is some kind of unintended side effect of how ERA works in game. I'll still use it as I'm bad at armor, but won't be super surprised if this gets changed/fixed soon, in the process probably making ERA mostly pointless again.

Oh, and I was thinking why do you have airgaps before ERA and placing them face forward, adding another small airgap for HEAT shells to release... Staggered ERA should be done in the same checkmate 2 layer sections as you have done but there should be NO airgaps before ERA block, they are not helping at all. Also why hide them behind HA if they are more efficient and effective then HA. I have currently found out that APFRAG leaved the best holes in staggered ERA (not mentioning pure AP rounds though). HESH could have been good but its too ineffective in general IMHO.

I've done lots of testing with ERA since I discovered the repair cost is 1/4 build cost. It doesn't work at all for me. ERA is great a stopping HEAT and HESH, but it does not stop my railguns at all. Idk what I'm doing wrong. I've tried staggered, backwards, multi-layers, and combinations of those setups. My railguns don't care. Also, I sooooooo wanted to enter the spaceship battle, but I'm not going to be able. Sorry.

Does it matter if the ERA is the normal verson or the sloped ERA?

why stager?