#most transport. some military. the convoy needs protection. from the raiders :)

[spearxwind]

Fantasizes about a really big excavator vehicle for my dragon worldbuilding before realizing im basically reinventing the plot in avatar

[banshee-king]

How to Repel a Space Marine Crusade:

Okay, so I’ve been thinking a lot about how to write a believable story involving thousands of Space Marines being defeat, because hey, it’s really fun to think of Space Marines dying in large numbers, but I’ve come up with a few scenarios which would result in major (if not 100%) casualties for a Space Marine crusade attacking a planet.

Many of these cases work for a race comparable to the Tau, though it could also work for other minor xenos races or an advanced human empire as well. Firstly however, I imagine the Space Marines (SMs from now on) would identify a number of critical locations for them to destroy, since they function best as a rapid striking shock force.

This is where things can immediately start to go wrong for them however. If a defending race knew the SMs were coming, and they knew a bit about the SMs, they could create a number of false locations for the SMs to strike, thus setting up a trap for them. They could claim their leader is in a location they’re not, or they could set up a superficial communications relay/power generator/supply depot that might look important, but is actually not essential and is merely a redundant decoy. This is useful for the following methods. 

Stage 1: Deployment

The SMs would then most likely deploy via one of two methods. Option 1 is to drop pods right on top of the enemy. Options 2 is to land thunderhawk transports outside a strategic location, unload all the SMs and their tanks, and then assault the city/base. Option 1 is usually impossible to stop, since drop pods are extremely difficult to shoot down. But there are two ways to deal with this.

Option A, what if there was a weapon that could fill the skies with thunder and lightning. Aside from being very very frightening, the lightning could be attracted to the metal drop pods and indiscriminately strike them. The ground forces don’t need to aim, they just turn on the machine, and anything that goes inside the lightning field will get hit. You don’t need to even destroy the drop pods, an EMP-like effect might disable the retro thrusters so that they can’t slow down and crash upon impact.

Option B is to lure them into a trap. Imagine a military base surrounded by fortifications. The SMs drop pod into the heart of the base, looking to kill the leader and scatter the enemy. But there is no leader to be found, and they are now surrounded by fortifications. Caught in the open, with the enemy entrenched, artillery raining upon them, aircraft striking from above, and no way of escape, the SMs would take heavy loses. This is somewhat similar to the Iron Cage, but I could see non-SMs pulling this off. They would only have dreadnoughts and devastators for heavy support, with no tanks at all, it would be painful and an easy way to kill of an entire company of SMs.

Stage 2: Harassment

But what if the SMs land away from enemy forces? Or with Thunderhawk transports? What happens when the SMs have landed with all their tanks and artillery? Well the key is to bleed to SMs of their numbers. Taking out as many thunderhawk transports would be great, it’s not impossible and could be used as one of many steps that lead to a SM defeat. But if the SMs do land in numbers and are on their way to their target location, probably a city or fortress of some kind, then the next step is to harass them, and I’m not talking verbally or sexually here. Again there are multiple options.

Option A, a xenos race that can burrow through the ground. The Tau might have access to this, or there could be some kind of technology that allows individuals to move through the earth. Regardless, if a planet had a population of 7 billion or something, you could easily have thousands of these guys. They could pop up amongst the SMs ranks, drop the equivalent of melta bombs or plasma/EMP grenades, and then they could jump back down into the ground. The potential damage of these guys would be devastating. The SMs can’t shoot these guys until after they’ve appeared, and even if the SMs do kill some of them, it won’t be enough to stop them. Bonus points if these burrowing units can stick a hand out of the ground, attach a melta bomb to the underside of a tank, and then disappear without the SMs even seeing them. That’s next level stealth.

Option B would be snipers, either in forests, atop hills, or some other hiding position. Tau pathfinders would be great for this, since they have access to Ion Rifles and Rail Rifles. Sniper units like these could rack up a huge tally against the SMs, perhaps even managing to take out tanks. Of course it would be ideal if the snipers had a set goal in mind, same with all the harassing units. If you can’t take out the Land Raiders, maybe you could disable its lascannon sponsons. Imagine is you damaged all the lascannons the SMs carried. It’s one of their longest ranged weapons, and their best defence against armoured targets. If you took out all the SMs lascannons, then struck them with an armoured convoy, they would be so screwed. Same if you took out their anti-air firepower then brought in aircraft to deal with them.

Option C is to use fast moving units like bikes or skimmers and harass the SMs with hit and run tactics. The SMs would have a much easier time defending against this though. Even still, it would bring their advance to a crawl, and getting form one city to another would be a bitch. Assassinating commander would be great, but immobilising vehicles would also work. Either the SMs have to stop and repair it, or leave the vehicles behind. Also, a combination of all three harassing tactics would be a nightmare to deal with. It would be cowardly perhaps, but it would be so effective. It wouldn’t work against Orks/Tyranids, they’re too numerous for it to matter and they’d catch the snipers. Eldar would be too fast and stealth as well. But SMs, slow and limited in number, every weapon and brother they lose would be devastating to their combat effectiveness.

Stage 3: Entrapment

Alas, what can you do if the SMs reach a city or military base? Well there are a few possibilities. If they’ve attacked a decoy location, you could plant a big bomb in the centre and then set it off when they’re right atop of it. Might not kill all of them, but again, every SM you kill matters. And it also might kill all of them, depending on the bomb and the size of the SM force.

Another effective strategy might be to lure them into a mine field in front of your base. Even better would be if the mines could be activated at the switch of a button. The SMs draw close, you wait. They get within range of your artillery, you wait. You wait until they have fully entered your range, and then you turn on the mines and shell them with artillery. Added bonus, call in the air support.

The SMs don’t have the greatest range on their guns, especially if your harassing units did their job and took out the longest ranged ones. But trapped in such a scenario, the commander has to choose to push the assault or fall back. If the SMs encounter the mines as they first walk into them, and then artillery starts hitting them, the commander might decide to fall back, taking little casualties. But if they’re drawn in first, if their entire force enters the mine field before it activates, no matter what they do they’ll lose far more marines.

Now multiple this across the globe, SMs harassed constantly no matter where they go, their targets turn out to be decoys, sometimes there’s nothing but a bomb that blows up in their face, other times they’re lured into mine fields with artillery and air support. I could see thousands of SMs dying of the course of a campaign. Of course they’ll adapt to these tactics eventually, yet then again, what can they do? What’s the counter to underground moving enemies? How can you be sure of the enemy’s true location if they’re constantly feeding you decoys and lies?

The above tactics I have mentioned only work for certain races when they’re defending a planet against the invading SMs however. I’ll do another post talking about what happens when SMs are defending a world like Armageddon, or Cadia, or Baal, or Macragge. I hope you’ve enjoyed this ramble though, it goes to show that SMs can be defeated, they’re far from the greatest force in 40k, even if the lore seems to go out of the way to protect them.