This will be the first of my tacticas to tap into the Heavy Support section of Codex: Space Marines. I will look at my favourite choices first, the Devastator Squad. Able to lay down a massive firepower while still keeping a high survivability, these guys are one of my favourite units of all time.
The first basic rule when it comes to Devastators is: don't mix the weapons. There are of course exceptions to this, but generally – it is best to stick with four of any one weapon when it comes to these guys. The squad on the box may look cool, with four different weapons, but if you mix the ranges and uses of all the weapons, you'll end up with a squad that has an unclear role. It is at best mediocre at taking care of infantry, and the same goes for heavier foes, tanks and so on.
Also, there are two weapons that clearly outshine the rest of them when it comes to cost efficiency and raw power: the Missile Launcher and the Heavy Bolter. I will discuss these two options later on.
The squad size is as important as ever, just going for five members – a Sergeant and four heavy weapon carriers is not enough. You will need at least one ablative wound for each heavy weapon carrier in the squad, so you don't have to remove all the expensive Missile Launchers and Heavy Bolters as soon as you start to take casualties. This usually means that a Devastator Squad will have four members with heavy weapons and four members with Bolters – one of them the Sergeant. Do not upgrade the Sergeant to carry anything unless it's for fluff purposes, the squad will rarely see Close Combat any way, and only then will a Power Fist pay off.
If you find yourself with spare points in a list, it is usually a good idea to get a pair of extra wounds in the squad. Eight is absolute minimal, but if you can get one or two more bodies in there, it's all the better since the Devastators will be a huge target for any enemy.
Missile Launcher Devastators:
The Missile Launcher Devastators are probably my favourites of all the configurations. They are versatile enough to deal with almost anything and they are relatively cheap. Four Missile Launchers will hurt against tanks, skimmers, light infantry (Gaunts, Boyz and so on) since it can fire two kinds of missiles.
They greatly benefit from veteran skills that are available through traits. Tank Hunters essentially makes the Missile Launchers as effective as Lascannons against tanks, and it keeps the versatility to kill hoards of enemy infantry. Also, they are still much cheaper than the Lascannons – a Lascannon squad will cost a whopping 260 points without any veteran skills, while the Missile Launcher + Tank Hunter squad weighs in at just 224 points.
The Lascannon only really out-performs the Missile Launcher when the Tank Hunters rule doesn't apply – against models with a T of 7 or more, or against models with a 2+ armour save.
Infiltrate is another great skill for any Devastator set-up, since they can move into a good spot in good 4+ cover and stick around there for most of the game. The only real threat to the squad if it's in cover is good assaulters.
Heavy Bolter Devastators:
These are even cheaper than Missile Launcher squad, and they are better at laying down medium infantry. The squad puts out 12 shots per turn in ranges 25"-36", 16 at 13"-24" and 20 at under 12", depending on the number of Bolter wielding Marines in the Devastator Squad.
This squad is also great with Tank Hunters. Heavy Bolters can be very, very effective at taking down light skimmers (Piranhas, Land Speeders), light Ork vehicles, Rhinos and so on when they have this trait to boot.
When firing at an AV 10 vehicle, this squad will on average score 4 damaging hits, and three of them will be penetrating – unless the vehicle benefits from something like Skimmers Moving Fast. Not bad for a bunch of Heavy Bolters, right?
Also note that this squad benefits as much from Infiltrate as the Missile Launcher squad.
What not to use:
I don't recommend anyone to use Lascannons, Multi-Meltas or Plasma Cannons in Devastator Squads. This is because all of these weapons are very expensive and in the case of the Multi-Melta, has such a limited range that not even Ìnfiltrate will get you close enough. Nobody in their right mind will move a vehicle into their kill zone either, so the four Multi-Meltas are wasted points.
Plasma Cannons are expensive, and they come with a risk. Since you will be firing all four in all six turns of a regular game, that totals in 2,66 dead Space Marines due to overheat. The Plasma Cannon is truly an awesome weapon though, since it has great strength and AP and a template to that. I'd take them in Tactical Squads though and leave the Devastators with Missile Launchers or Heavy Bolters.
The same thing applies to Lascannons. An effective weapon, but it comes at a hefty price. Carrying around Lascannons is really work for Tactical Squads as well, although a Devastator Squad with 4 Lascannons and Tank Hunters will make short work of any vehicle that cross their path.
"One of these too, sir?"
When it comes to mixing weapons, take it really easy. The Heavy Bolter and the Missile Launcher both have decent points cost, but the rest are very, very expensive. I have personally had some success with a squad that contained 3 Missile Launchers and a single Lascannon, paired up with Tank Hunters. The Lascannon helped out a lot against tougher vehicles, such as Leman Russes. Note though that the Tank Hunters skill is useless against the Necron Monolith.
If you've got the set-up right, you're already halfway there. From there, you need to keep two things in mind: where to deploy the Devastators and in which order to shoot at things.
Deployment is easier with Infiltrate, but try and get a good place with a decent cover save, and some good fire lanes. The squad is very static, so you won't be moving it around. Infiltrate is all the mobility Devastators gets, and from there, it's a matter of just pointing at what targets you want to shoot out. Also, picking targets in the game is easier when you have Infiltrate. Since you will deploy the Devastators early otherwise, your opponent will not place any good targets in a fire lane of the Devastators any time soon. If you have Infiltrate though, chances are that the best targets for your units are already on the board – which means that you can choose what to shoot at in the Infiltration phase.
Your Devastators will hopefully have a clear role when it comes to shooting. Pick the targets you are most likely to do good damage on, and take care of the fastest unit first, before you start to shoot at slower opponents. This will change depending on the armies of course – if you play against Tyranids, you will want to shoot at the synapse creatures first, and so on. This is just a rule of thumb to keep in mind.
As I said first in this article, Devastators are perhaps my favourite Heavy Support choice in Codex: Space Marines. They have the survivability of a Tactical Squad paired up with the firepower of a Predator or better. They can't be shaken or stunned, and as we all know, Marines generally have few moral problems. This makes them one of the best units in the codex in my opinion, and should be considered in most lists built on static firepower and infiltration.