AbusePuppy has recently taken us through Quantum Shielding and all that it entails for a Necron army (both playing it and playing against it). Of particular note of course is the durability Necron vehicles have with Quantum Shielding and Living Metal. Beyond this, a lot of parallels have been drawn between Living Metal and Grey Knight's Fortitude and for obvious reasons - they both counter suppression. Suppression is a key part of 5th edition as enemy vehicles are so common. It's not that rare to see 10+ vehicles in your opponent's army or 20+ on the table during deployment (even at 1500 points). What Living Metal and Fortitude allow is the respective Necron and Grey Knight armies to care less about suppression for their own army. This is an interesting development if the designers are indeed thinking with 6th edition in mind (I'll believe that when I see it), particularly with Eldar around the corner (remember the good old Spirit Stones?).
Anyway, what this post is going to examine is the differences between Living Metal and Fortitude - not to determine which is better but what the strengths and weaknesses of each are.
Fortitude -
The best thing about Fortitude is it happens during your turn. This means your opponent is unsure whether or not the vehicle in question is going to be suppressed or not during their shooting phase which brings them to an interesting conundrum - do I keep shooting the tank for further suppression/aim for the kill (i.e. weapon destroyed or better) or do I spread my firepower around and hope some of the Fortitude tests are failed? The general rule of thumb is the latter - force your opponent to make more rolls and they are more likely to fail. However, like vehicles with extra armor, Power of the Machine Spirit, etc. sometimes a vehicle just needs to be stopped and with Fortitude the opponent can never be sure this is going to happen with only shaken or stunned results. This can thereby cause them to put more firepower into the unit than necessary.
Fortitude is also a psychic power cast on Leadership 10. This is a double-edged sword as it becomes very reliable (1/12 fail) but can be stopped by psychic defenses. This reliability plays into the hands of the point above - your opponent doesn't know if it's going to be successful until your turn and if the opponent has only applied shaken or stunned results, the dice are likely to fall in the Grey Knight player's lap. However, if the opponent has psychic defenses the equation changes a bit. Fortitude becomes closer to a 50/50 chance than an actual sure thing and whilst this may seem like a loss for Grey Knights, considering the five point cost (in relation to other Space Marine vehicles), this is still a pretty damn good deal. Psychic defense does reduce Fortitude's effectiveness but the opponent still doesn't know if the defenses are going to stop Fortitude or not until the issue is out of their hands. Grey Knights are still sitting pretty.
However, psychic defense which causes damage (i.e. Shadow in the Warp and Runes of Warding) can basically stop the power from even being attempted. You really want to risk taking extra glancing hits and immobilise yourself? Lose your weapons? I don't think so. The major issue with this weakness of Fortitude is of course the fact that such psychic defenses are not common and Runes of Warding is sure to get a distance nerf when their new codex comes around. Off-setting this of course though is the base chance Fortitude has to generate damage by itself thanks to Perils in the Warp on double 1's or 6's (or a 1/18 chance). If you have 10+ tanks in your army all casting Fortitude, odds are you're going to fail some tests and some of them are going to cause Perils and do further damage to your tanks. It's a minor off-set considering the massive bonuses Fortitude grants vehicles but it is an off-set.
Living Metal -
Living Metal is really the exact opposite to Fortitude in terms of application. Rather than happening during the owning player's turn, Living Metal happens as damage is inflicted. The effect of this is two-fold. First, Living Metal means the controlling player is always going to be rolling more dice to stop effects. Fortitude rolls one psychic test no matter how many shaken/stunned results are applied in a given turn whilst Living Metal is rolled as they occur. This means results are far more likely to get through (particularly stunned results). Second, it means your opponent knows what they are facing in the up-coming turn - specifically, which tanks aren't shooting, moving or both. This is a huge down-side of Living Metal compared to Fortitude.
On the flip side of things however, Living Metal is never going to hurt your own tanks. You may make more rolls for Living Metal compared to Fortitude and your opponent may have a greater understanding of what they are dealing with next turn but Living Metal is an ability you are always going to use - there are no negative consequences. Furthering this, since Living Metal isn't a Psychic Power, it is far, far more reliable in removing shaken results compared to Fortitude when there are Psychic defenses around. Living Metal is even more reliable at removing Stunned results depending upon the type of Psychic defense. This is of course mitigated by more rolls needing to be made but again, it's an ability you are always going to have access to and there is no down-side to using it - it's just something that kicks in whenever such results are applied.
But there's more...
Based on this analysis Fortitude does seem the better ability - one roll to rule them all though Living Metal is a better mechanic I believe (you know what's happening as it happens). Whilst Living Metal means your vehicles are rarely ever going to be shaken, the amount of rolls they need to make for Shaken and Stunned results compared to the one roll of Fortitude can drag their effectiveness down. This includes Fortitude being tempered by Psychic defenses. However, what this comparison doesn't include is Quantum Shielding or specifically that the average AV of the Necron army is higher than that of the Grey Knights. With AV13 front and sides on all the vehicles except Monoliths (AV14 all-round) and the two Scythe variants (AV11 all-round), less damage is going to be taken compared to the average AV11 Rhino/Razorbacks and AV12 Dreadnoughts of the Grey Knights. This means they are less likely to be rolling a ton of Living Metal rolls on Shaken and Stunned results.
This balances the effects of Living Metal across the army in relation to Fortitude. There are still AV11 vehicles out there and Quantum Shielding isn't eternal, but based upon the unique army constructs (and especially when there is psychic defenses around), the two play off each other quite well. There are advantages and disadvantages to both and there are situations when one is better than the other.
Conclusion and Opposing Armies
The ultimate conclusion of this analysis is pretty basic - Fortitude is generally the better ability but limited by it's psychic power application (and thus can cause further damage and is vulnerable to psychic defenses) whilst Living Metal is seen more on higher AV platforms and has no drawbacks. Ultimately they both limit the amount of suppression the opponent is capable of inflicting.
And this brings us to a very important point - how do opposing armies deal with suppression resistant armies? Both of these armies also have good Leadership across the board so their infantry is hard to make run away or become pinned (so blowing up their tanks doesn't throw their army into the dirt). For armies built around a lot of suppression fire like Dark Eldar or Tyranids, this can be a big problem but in reality it simple moves the goalposts. Generally when shooting at enemy vehicles once you hit a shaken or stunned result (depending upon the vehicles purpose), you leave said vehicle alone. There are exceptions but its a good general rule of thumb to live by. With suppression resistant vehicles this always isn't the case however and the end result you as an opponent may often be looking for is a weapon destroyed or higher result. It is very much a case of how long is a piece of string - each scenario is going to be different but remember the key differences between the two abilities. If you cause more suppression damage against Grey Knights, they are more likely to fail psychic tests and suffer perils of the warp and if you case more shaken/stunned results against Necrons, some will go through and you will know exactly when they go through and can thus maximise your firepower.
Yes suppression resistant vehicles are annoying but suppression resistant is not suppression immune nor does it increase the odds of the vehicle actually surviving. If you bring high strength, AP1 weapons along, tanks will die and their suppression resistance be damned.
