Forum adverts like this one are shown to any user who is not logged in. Join us by filling out a tiny 3 field form and you will get your own, free, dakka user account which gives a good range of benefits to you: No adverts like this in the forums anymore. Times and dates in your local timezone. Full tracking of what you have read so you can skip to your first unread post, easily see what has changed since you last logged in, and easily see what is new at a glance. Email notifications for threads you want to watch closely. Being a part of the oldest wargaming community on the net. If you are already a member then feel free to login now.

Partly due to the influx of AP2 destroying Terminators completely, I have just though of a rough idea of how to change the way AP ignores armour.
So, my idea is that:
An AP value higher than the Armour Save doesn't affect it, the target receives the save.
An AP value equal to the Armour Save forces a reroll of a successful Armour Save check against it.
An AP value lower than the Armour Save ignores the save, the target gets no save.

So, a Space Marine (Sv3+) hit by an autocannon round (AP4) receives a 3+ armour save.
If hit by a krak missile (AP3), he gets a 3+ save, but must reroll if he passes.
However, if he is hit by a lascannon (AP2), he gets no armour save at all.

Thoughts? It probably does need fine tuning!

How about changing tactics on how you use your Terminators? I mean, think of this as real life. I mean you don't change the rules because you are loosing. You have to adapt.

Are you wanting to change the rules because you can't adapt or you don't want to change your play style?

With that being said and you are accepting "house rules" and you would accept others or mine rules, then I would say Yes, you rule is great there.

Problem is with rerolling a 2+ means you will most likely save it next roll, how about that roll is a 4+. A 50/50 chance to make it more fair for someone having a AP2 weapon and paying the points for it.

After all how would you feel you pay the points for the unit that should be able to take your Terminators down but they fail all the time because of a 2+ save. This way you get what you want, another chance, but the person has a good chance of you failing your "resave or reroll".

Davor wrote:
How about changing tactics on how you use your Terminators? I mean, think of this as real life. I mean you don't change the rules because you are loosing. You have to adapt.

Are you wanting to change the rules because you can't adapt or you don't want to change your play style?

With that being said and you are accepting "house rules" and you would accept others or mine rules, then I would say Yes, you rule is great there.

Problem is with rerolling a 2+ means you will most likely save it next roll, how about that roll is a 4+. A 50/50 chance to make it more fair for someone having a AP2 weapon and paying the points for it.

After all how would you feel you pay the points for the unit that should be able to take your Terminators down but they fail all the time because of a 2+ save. This way you get what you want, another chance, but the person has a good chance of you failing your "resave or reroll".

You are making lots of unhealthy assumptions. Your suggestion is sound, but you expecting that he suggested this just because he wants a stronger army is a bit too dismissive for my tastes.

Still don't like it. I'll agree the Armor Save is a bit antiquated now that things like Wraithknights and Riptides shrug off 40+ shots of AP3 the same as they shrug off lasgun fire that has no AP at all. Could do with some modifiers of Armor saves the more shots are used but I have no real idea on how to do that fairly.

 Ashiraya wrote:

Davor wrote:
How about changing tactics on how you use your Terminators? I mean, think of this as real life. I mean you don't change the rules because you are loosing. You have to adapt.

Are you wanting to change the rules because you can't adapt or you don't want to change your play style?

With that being said and you are accepting "house rules" and you would accept others or mine rules, then I would say Yes, you rule is great there.

Problem is with rerolling a 2+ means you will most likely save it next roll, how about that roll is a 4+. A 50/50 chance to make it more fair for someone having a AP2 weapon and paying the points for it.

After all how would you feel you pay the points for the unit that should be able to take your Terminators down but they fail all the time because of a 2+ save. This way you get what you want, another chance, but the person has a good chance of you failing your "resave or reroll".

You are making lots of unhealthy assumptions. Your suggestion is sound, but you expecting that he suggested this just because he wants a stronger army is a bit too dismissive for my tastes.

Unhealthy assumptions? Yes. Even though this being the internet, it doesn't excuse anyone from explaining themselves properly. So with this being the internet and we have to guess why, it's always easier to fuss that it's more "I can't use this, needs to be easier" without a proper explanation. Sadly I look at it in more of a negative way, but hoping to turn this into a positive so that the OP would next time, take the extra minute and explain why he feels it unfair.

For my part, if I thought he just wanted a stronger army I wouldn't have taken the time to give him my view on how to fix it. I gave him the benefit of the doubt, he is not that kind of player, just wished he explained himself more so I could help him, would make it more easier to see where he was coming from.

Davor wrote:

 Ashiraya wrote:

Davor wrote:
How about changing tactics on how you use your Terminators? I mean, think of this as real life. I mean you don't change the rules because you are loosing. You have to adapt.

Are you wanting to change the rules because you can't adapt or you don't want to change your play style?

With that being said and you are accepting "house rules" and you would accept others or mine rules, then I would say Yes, you rule is great there.

Problem is with rerolling a 2+ means you will most likely save it next roll, how about that roll is a 4+. A 50/50 chance to make it more fair for someone having a AP2 weapon and paying the points for it.

After all how would you feel you pay the points for the unit that should be able to take your Terminators down but they fail all the time because of a 2+ save. This way you get what you want, another chance, but the person has a good chance of you failing your "resave or reroll".

You are making lots of unhealthy assumptions. Your suggestion is sound, but you expecting that he suggested this just because he wants a stronger army is a bit too dismissive for my tastes.

Unhealthy assumptions? Yes. Even though this being the internet, it doesn't excuse anyone from explaining themselves properly. So with this being the internet and we have to guess why, it's always easier to fuss that it's more "I can't use this, needs to be easier" without a proper explanation. Sadly I look at it in more of a negative way, but hoping to turn this into a positive so that the OP would next time, take the extra minute and explain why he feels it unfair.

For my part, if I thought he just wanted a stronger army I wouldn't have taken the time to give him my view on how to fix it. I gave him the benefit of the doubt, he is not that kind of player, just wished he explained himself more so I could help him, would make it more easier to see where he was coming from.

To be fair, the forum is filled with posts explaining how bad Terminators are. I can see why he did not see the need to repeat them.

I can explain to you if you do not want to look after them, though.

 Ashiraya wrote:

To be fair, the forum is filled with posts explaining how bad Terminators are. I can see why he did not see the need to repeat them.

I can explain to you if you do not want to look after them, though.

LOL, I must have got 2 threads mixed up into one. I just answered you on the other thread my friend.

Love a good friendly discussion.

I wish it worked more like Fantasy, with different rules that further modify how armor saves are taken, with plasma applying a larger modifier than an equally strengthed autocannon.

That's make some enemies far to hard to kill. In fact, since there are so few AP1 Weapons to begin with, anyone with a 2+ Armor Save gets something about as tough as a 3+ Invuln, for free. Meganobz, for example, would become ludicrously good.

 Lord Commissar wrote:
I wish it worked more like Fantasy, with different rules that further modify how armor saves are taken, with plasma applying a larger modifier than an equally strengthed autocannon.

Never played Fantasy so not sure how it goes, but get the gist now. I like this idea. After all, you are HIT. So how come when you are hit, you roll again to not become hit? I can understand you are Hit, then your armour will see if you take damage. I can't understand how if the weapon can go through your armour, how the cover save helps because you are already hit. How is a bush or say smoke going to help you survive a weapon attack that will go through your armour? You are HIT. Now that bush or smoke helps you after you get hit? I never understood this theory.

Davor wrote:


Never played Fantasy so not sure how it goes, but get the gist now. I like this idea. After all, you are HIT. So how come when you are hit, you roll again to not become hit? I can understand you are Hit, then your armour will see if you take damage. I can't understand how if the weapon can go through your armour, how the cover save helps because you are already hit. How is a bush or say smoke going to help you survive a weapon attack that will go through your armour? You are HIT. Now that bush or smoke helps you after you get hit? I never understood this theory.

You're thinking of it as if things are happening in real-time. That's simply not how it works. Rolling to hit, rolling to wound, rolling armor save or cover is just how the game is played, not how events happen with real weapons against real targets. It's all about chance to wound, amount of wounds, prevented wounds where a wound is a simple tally mark. It's stats in a game and has no real equivalent in the way things actually work. Better way to look at is all revolving around the idea of the wound itself. How many wounds does the attacker have the chance to make (to hit). How many wounds get made (to wound). How many does the defending player prevent (armor and cover saves). No point in thinking of it like 'Well the bullet hit him but now it didn't because it's dark outside'.

if i was going to implement a new AP system to replace the strength based armour modifiers of WHFB.(3rd ed 40k.)

I would implement it like this.
The AP value ignores the save rolls equal or higher than its value.

EG a Sm saves on a 3,4,5,or 6 normally.

An AP 6 weapon removes all dice that roll a 6 to save.
So the Sm only saves on 3,4 and 5.

An AP 5 weapon removes all saves that roll 5 or 6 to save..
So the Sm only saves on a 3 or 4.

This mimics the results of additional armour modifiers , but removes all the maths , and replaces them with simple dice removal.

However, If I was allowed to re do the whole armour and weapon interaction , I would simply extend the values in the game to cover ALL units, 15 armour values and 15 Armour penetration values for example.
Use them as opposed values to generate the save in a proportional way.(Similar to armour in F.O.W)

 SharkoutofWata wrote:

Davor wrote:


Never played Fantasy so not sure how it goes, but get the gist now. I like this idea. After all, you are HIT. So how come when you are hit, you roll again to not become hit? I can understand you are Hit, then your armour will see if you take damage. I can't understand how if the weapon can go through your armour, how the cover save helps because you are already hit. How is a bush or say smoke going to help you survive a weapon attack that will go through your armour? You are HIT. Now that bush or smoke helps you after you get hit? I never understood this theory.

You're thinking of it as if things are happening in real-time. That's simply not how it works. Rolling to hit, rolling to wound, rolling armor save or cover is just how the game is played, not how events happen with real weapons against real targets. It's all about chance to wound, amount of wounds, prevented wounds where a wound is a simple tally mark. It's stats in a game and has no real equivalent in the way things actually work. Better way to look at is all revolving around the idea of the wound itself. How many wounds does the attacker have the chance to make (to hit). How many wounds get made (to wound). How many does the defending player prevent (armor and cover saves). No point in thinking of it like 'Well the bullet hit him but now it didn't because it's dark outside'.

I try, I did try. I just can't do it. For me, you roll to hit, if hit, roll to save, then once the save is failed, then roll to wound. To me that means the bullet for example went through the wall or penetrated the armour and now the roll to wound is to see if it hit a vital component and you die, or it's it's a flesh wound but you can still survive and continue combat.

So if we are going to keep a save roll it should go before the wounds? But then again this doesn't help the OP. Now I can't remember where I read this, (too many thread I read on the weekend) someone said that cover can give you an obscurant like a bush so it's a +1 to hit, while a wall can give you a +1 to hit and a +2 to wound.

I'm not sure that the way to correct AP2 spam is to make terminators basically unkillable.

Essentially by your thinking a terminator could only reliably die to melta and a few of the rare AP1 weapons that exist. Rolling a 2+ twice is no benefit to the attacker taking AP2 weapons. Might as well stack mass low AP shooting and hope for 1s.

Meanwhile everything that doesn't get marine saves on the regular is forced to die like usual to AP2 weapons, of which every terminator gets stock.

If anything the best solution is to make AP a modifier, like the vehicle table.

AP1 = -5 to save
AP2 = -4 to save
AP3 = -3 to save
AP4 = -2 to save
AP5 = -1 to save

But this ultimately means that everything is getting a 6+ invuln unless they're pushed above 6, which is problematic in its own right.

Definitely not calling out the OP, but in my experience the biggest problem with termies is misuse. It seems a lot of players look at 2+/5+ and thing "unkillable" so they stop playing tactically with them, assuming they'll soak up everything thrown at them and they'll in turn kill.

I swear, playing Dark Eldar was the best thing to make me play more tactically. Being forced to deal with fragility can make you deadly with good saves in hand.

@OP I suggested the exact same thing a while back. Its a pretty logical fix for the rules IMO

http://www.dakkadakka.com/dakkaforum/posts/list/589104.page

Honestly, I'm having a really hard time understanding how this makes sense at all, and respectfully as possible I'd like someone who's a proponent to tell me why this isn't simply a huge unnecessary buff to MEQ/TEQ with no equivalent upside for non-Marine armies.

Right now a single terminator has a chance to survive an AP2 wound 33.3% of the time thanks to a 5+ invulnerable save. Changing that to a 2+ forcing a reroll makes those odds skyrocket to 69.44%.

If a unit with 3+ armor is wounded with an AP3 weapon they die, 0% chance of save right now. Your suggested change increases the odds to 44.4%

Lets continue:
4+, AP4: 0% to 25%
5+, AP5: 0% to 11.1%
6+, AP6: 0% to 2.78%

So basically this suggested change is the biggest balance swing the game would see, but only to armies with mass amounts of 2+ and 3+ armor, aka Marines and Marines only.

That's before we even begin to factor in SM's higher toughness than most units, and almost no threat of leadership failure.

In short: This would break 40k.

I have a bit of a radical change to Save & AP interaction that requires no change to unit entries, just another chart (when I get around to making one).

It would be fairly metagame-altering as survivability for infantry would increase. Basically, against shooting, all saves become more survivable overall, ignoring cover, except 2+ saves which overall remain the same. In assault, having an AP value really matters with these changes.

Now to state the changes.

Basically the Sv value becomes an armor rating (AR), and the rating is compared to the AP to determine the armor save.

All armor is rated against bolters. This is to say the save against AP 5 weapons is the armor rating.

For the rest you can think of it three ways.

First as a formula, AR - AP + 5. If the result is greater than 6 there is no save. Otherwise the result is the save, with 2+ being the best you can get.

Second as modifiers, AP 5 is 0, AP 4 makes your save one worse (+1), AP 6 makes your save one better (-1). The pattern contiues, AP 3 is +2, 2 is +3, 1 is +4, and AP '-' is -2.

Thirdly, if AR = AP the save is 5+. If AP is one better than the AR the save is 6+. If the AP is more than one better than AR there is no save. The same is true in the opposite direction to a maximum of 2+.

A chart would make explaing this easier.

Then there are changes to cover. Strong cover (ruins, rock formations, dense foliage, etc.) grant a +1 to armor save rolls (6+ if there is no save). Fortified cover (fortifications and the like) grant a +2 to armor save roll (5+ if there is no save). This is on a model to model basis to a maximum of a 2+ save.

Also there is concealment. Being concealed gives a -1 BS modifier, however the whole unit must be partially obscured, gone to ground, or in area terrain to gain this benefit. Stealth gives an extra -1 BS when concealed. Shrouded grants concealment.

Finally to counter this increased survivability, weapon profiles with the melee rule grant -1 to the armor save roll, negating saves that would be normally 6+. Another reason for this is because a majority of melee attacks are AP '-' and infantry would be way too survivable in the assault phase. This is also a big boost to melee weapons that have AP.

AP values have new shooting roles with these changes. AP 3 & 4 are more efficient anti-infantry. AP 1 & 2 are better for anti-vehicle and less efficient against heavy infantry, but still work. AP 5 and 6 are really only good against light infantry. AP '-' bounces off most armor and is really only good en masse. Same goes for CC but shift all the APs up a number. AP 1 ignores armor saves altogether in melee.

Davor wrote:

So if we are going to keep a save roll it should go before the wounds? But then again this doesn't help the OP. Now I can't remember where I read this, (too many thread I read on the weekend) someone said that cover can give you an obscurant like a bush so it's a +1 to hit, while a wall can give you a +1 to hit and a +2 to wound.

That depends on what you mean by "should." The mathematical probability is the same no matter what order you go in, and doing it in any order is the same as using a different color die for each step and rolling them all at once.

The order should be the way it is because it's easier for one player to finish all his rolling before the other player goes.

 Auswin wrote:
I'm not sure that the way to correct AP2 spam is to make terminators basically unkillable.

Essentially by your thinking a terminator could only reliably die to melta and a few of the rare AP1 weapons that exist. Rolling a 2+ twice is no benefit to the attacker taking AP2 weapons. Might as well stack mass low AP shooting and hope for 1s.

Meanwhile everything that doesn't get marine saves on the regular is forced to die like usual to AP2 weapons, of which every terminator gets stock.

If anything the best solution is to make AP a modifier, like the vehicle table.

AP1 = -5 to save
AP2 = -4 to save
AP3 = -3 to save
AP4 = -2 to save
AP5 = -1 to save

But this ultimately means that everything is getting a 6+ invuln unless they're pushed above 6, which is problematic in its own right.

Definitely not calling out the OP, but in my experience the biggest problem with termies is misuse. It seems a lot of players look at 2+/5+ and thing "unkillable" so they stop playing tactically with them, assuming they'll soak up everything thrown at them and they'll in turn kill.

I swear, playing Dark Eldar was the best thing to make me play more tactically. Being forced to deal with fragility can make you deadly with good saves in hand.

I like this idea. So if we give this rule to Termies, then everyone thing should have a 5++ then. After all if you give a buff to terms, and they are not going to use their 5++ save then give the 5++ save to everything else, Gaunts, Grots everybody. If they already have a ++ save then they get to reduce it. Only fair I think.

How does that sound?

Davor wrote:

 Auswin wrote:
I'm not sure that the way to correct AP2 spam is to make terminators basically unkillable.

Essentially by your thinking a terminator could only reliably die to melta and a few of the rare AP1 weapons that exist. Rolling a 2+ twice is no benefit to the attacker taking AP2 weapons. Might as well stack mass low AP shooting and hope for 1s.

Meanwhile everything that doesn't get marine saves on the regular is forced to die like usual to AP2 weapons, of which every terminator gets stock.

If anything the best solution is to make AP a modifier, like the vehicle table.

AP1 = -5 to save
AP2 = -4 to save
AP3 = -3 to save
AP4 = -2 to save
AP5 = -1 to save

But this ultimately means that everything is getting a 6+ invuln unless they're pushed above 6, which is problematic in its own right.

Definitely not calling out the OP, but in my experience the biggest problem with termies is misuse. It seems a lot of players look at 2+/5+ and thing "unkillable" so they stop playing tactically with them, assuming they'll soak up everything thrown at them and they'll in turn kill.

I swear, playing Dark Eldar was the best thing to make me play more tactically. Being forced to deal with fragility can make you deadly with good saves in hand.

I like this idea. So if we give this rule to Termies, then everyone thing should have a 5++ then. After all if you give a buff to terms, and they are not going to use their 5++ save then give the 5++ save to everything else, Gaunts, Grots everybody. If they already have a ++ save then they get to reduce it. Only fair I think.

How does that sound?

The problem is that you'd have to revalue every unit with an invulnerable save of 5++ or worse.

Don't bother revalueing every unit. The way I see it, is if a 5++ is not good enough and you want something better, then the person shouldn't have a problem giving everyone a 5++ then.

Davor wrote:
Don't bother revalueing every unit. The way I see it, is if a 5++ is not good enough and you want something better, then the person shouldn't have a problem giving everyone a 5++ then.

It also throw a wrench in cover mechanics, makes the demon rule a nerf for the most part, and makes armor 5+ and 6+ pointless. A 5++ for everything is too good really.

Whilst I am happy with the constructive criticism made here, I am quite taken aback by the assumptive, and rather unfair, comments actually directed at me. I believe I do use my Assault Termies well on the rare occasions I use them, embarking them in a Land Raider Crusader and charging into high point, bad CC units. This works well, but it is the abundance of AP2 and not AP1 that made me think of this solution to other players losing high point units to ludicrously low cost AP2. If AP2 was in some way weaker than AP1, against armour saves, I'd be happier. Also, Imperial Guard and other 5+ save lists rarely get that save, given the high amount of AP5 infantry rifles. Giving some, if meagre, protection might be a nice touch.

Davor wrote:
Don't bother revalueing every unit. The way I see it, is if a 5++ is not good enough and you want something better, then the person shouldn't have a problem giving everyone a 5++ then.

5++? Sure. Priced appropriately, of course.

 Sgt_Smudge wrote:
Partly due to the influx of AP2 destroying Terminators completely, I have just though of a rough idea of how to change the way AP ignores armour.
So, my idea is that:
An AP value higher than the Armour Save doesn't affect it, the target receives the save.
An AP value equal to the Armour Save forces a reroll of a successful Armour Save check against it.
An AP value lower than the Armour Save ignores the save, the target gets no save.

So, a Space Marine (Sv3+) hit by an autocannon round (AP4) receives a 3+ armour save.
If hit by a krak missile (AP3), he gets a 3+ save, but must reroll if he passes.
However, if he is hit by a lascannon (AP2), he gets no armour save at all.

Thoughts? It probably does need fine tuning!

Basically invalidates ap2 weaponry against 2+ guyz. And now there's gona be no need in assault termies cause 3++ isn't needed when 2+ with rerolls of sucksessful is actually better than 3++.

If you want to use such rules, you should seriously increase the cost of 2+ saves.

Oh, and go kill my 2-wound meganobz without melta.

This idea is interesting but it won't work without serious reballancing and repricing. The big part of game's ballance is built around current ap system. Changing it will bring way more troubles than we have atm.

Yep, i'm not happy with the ammount of easy ap2 invalidating tactical termies and stuff. But it's probably easier to make this ammount of ap2 more sane and less out of controle than change how ap2 works itself.

 Sgt_Smudge wrote:
Partly due to the influx of AP2 destroying Terminators completely, I have just though of a rough idea of how to change the way AP ignores armour.
So, my idea is that:
An AP value higher than the Armour Save doesn't affect it, the target receives the save.
An AP value equal to the Armour Save forces a reroll of a successful Armour Save check against it.
An AP value lower than the Armour Save ignores the save, the target gets no save.

So, a Space Marine (Sv3+) hit by an autocannon round (AP4) receives a 3+ armour save.
If hit by a krak missile (AP3), he gets a 3+ save, but must reroll if he passes.
However, if he is hit by a lascannon (AP2), he gets no armour save at all.

Thoughts? It probably does need fine tuning!

Wow, this is a great idea, especially with the retention of invulnerable saves.

Also, think how rare it is that an Ork gets to enjoy his 6+ armor, even sluggas are AP 6!

 Sgt_Smudge wrote:
Whilst I am happy with the constructive criticism made here, I am quite taken aback by the assumptive, and rather unfair, comments actually directed at me. I believe I do use my Assault Termies well on the rare occasions I use them, embarking them in a Land Raider Crusader and charging into high point, bad CC units. This works well, but it is the abundance of AP2 and not AP1 that made me think of this solution to other players losing high point units to ludicrously low cost AP2. If AP2 was in some way weaker than AP1, against armour saves, I'd be happier. Also, Imperial Guard and other 5+ save lists rarely get that save, given the high amount of AP5 infantry rifles. Giving some, if meagre, protection might be a nice touch.

Definitely not trying to go after you mate, just trying to understand how this helps the game in a real sense.

Personally, I'd love my Kabalite warriors, Wyches and Wracks to not immediately die to bolter fire -- but not at the expense of having to deal with practically unkillable terminators. The odds of passing 5+ twice are so low that the payoff isn't worth it. Maybe it will save one or two 9-12 point models -- that's it. Meanwhile a terminator squad could get barraged with AP2 and AP1 and barely lose a model.

Look at it in terms of CC against units that don't wear termie armor.
- Terminator captain w/ thunder hammer vs. Ork warboss w/ power klaw and 'eavy armor: Both are unwieldy. Swing at the same time, assume both do 3 wounds. Warboss's armor doesn't stop it, he's dead from being doubled out. Terminator has to make three 2+ saves (83% chance of passing) then make three re-rolls 69% chance of passing. The warboss gets no chance to live, the Terminator gets a 69.4% chance.

This is essentially the same for any unit with an AP2 weapon but poor armor. The diminishing returns on such a rule change vastly favor good armor and do little for bad armor. Given that the payoff for bad armor is typically mass (orks, nids etc) or high AP firepower (DE) you're gimping armies for no good reason.

Let's not lose ourselves in details here. Instead, consider OP's idea of a reroll at all. We could cap this reroll at 4+ or 5+ and still have it be helpful. Even if your save is reduced to 50% or 33% effectiveness, it is still a boon.

 Ashiraya wrote:
Let's not lose ourselves in details here. Instead, consider OP's idea of a reroll at all. We could cap this reroll at 4+ or 5+ and still have it be helpful. Even if your save is reduced to 50% or 33% effectiveness, it is still a boon.

The problem with the reroll, aside from the extra dice rolling, a 2+ save benefits the most the change. This is especially true with all the AP 2 floating around the metagame. That is unless you inverted the reroll, so a successful 2+ would have to reroll on a 6+ against AP 2 and a successful 6+ would reroll on a 2+ against AP 6. This doesn't address that you'd be rerolling the 2+ more often than anything else (except maybe 5+'s because of bolters).

I still think save modifiers are the way to go as long as pushing you over 6+ negates the save and you can't get better than a 2+.

I personally like

AP 1 = -4
AP 2 = -3
AP 3 = -2
AP 4 = -1
AP 5 = 0
AP 6 = +1
AP - = +2

This leaves 2+ the same on average while buffing every thing else with armor, with 4+ getting the most benefit + ~22% on average.

AP 2 would be worse against highly armored infantry (2/3 effective against 2+), but AP 4 would be much better (twice as good against 2+). All while still keeping AP 2 statistically better than AP 4, just less efficient.

You could -1 from the above modifiers, making AP 6 the 0. This would only make each save 4+ and up about 5% better on average, though it would make 3+ 3-4% worse and 2+ about 23% worse on average. Though I'd rather not nerf any armor saves on average.

The first set of modifiers would be brutal for melee weapons as they are mostly AP - which would turn 4+ into 2+. An extra -1 to the save for melee weapons would help there. That would also give the assault phase a bit of a damage boost over shooting. It also makes non-axe power weapons desirable again.

Your suggestion makes weight of fire even more obvious as anti-Terminator tactics, since against lasguns, effectively carapace becomes TDA but TDA still caps out at 2+.

Your solution would only magnify the problem.