Script for Basics: IEDs (Patreon)

A nice, straightforward mechanical CM one for a change. There's quite a lot of depth here for a system that is somewhat mission-design incompatible because of its randomness.

Basics: IEDs

Welcome back to Combat Mission Shock Force 2 where we are going to take a look at how IEDs work. I already covered this in the Unconventionals unit guide, but it’s not only buried in there but actually almost 6 years old, so it could do with a refresh.

IED stands for Improvised Explosive Device. In reality that could be almost anything, in our Combat Mission context we’re dealing with three broad types: IED mines, remote detonated IEDs and vehicle-borne IEDs. These all work in slightly different ways, but the key thing to bear in mind is the ‘Improvised’ part.

Fundamentally, an IED is less reliable and harder to use effectively than a more conventional weapon system. If we need to, for example, destroy an enemy vehicle, it is much easier to deploy an ATGM, bring up a tank, direct artillery or drop a JDAM than it is to rely on IEDs. IEDs are used when better options are not available, usually because the enemy has such a degree of overmatch that conventional means cannot be used.

IED Mines

The first and simplest type of IED modelled is an IED mine. This basically works like a conventional minefield, except that there is one large explosive instead of multiple smaller ones. They are victim activated- meaning they detonate when someone steps on them or drives over them.

This is the big advantage of the IED mine compared to the other types we’re going to look at: you don’t have to babysit them, they just sit there. They are, however, not 100% reliable. As opposed to minefields which have a lot of potential trigger points, there’s a much lower chance that some unlucky pixeltruppen will find the single IED mine.

They are very effective when they go off though- individually less of an area denial weapon like conventional mines, more a means of inflicting casualties.

Remotely Activated IEDs

The second type of IEDs are remotely activated ones. These are significantly more complicated than IED mines. The IEDs themselves come in different sizes, they have different trigger mechanisms and they can only be detonated by a triggerman, who must both be in range and able to see the target unit in order to set the IED off.

Size

That’s quite a lot of stuff. Breaking it down, first we have the different sizes of IED: small, medium, large and huge.

Small IEDs look like they’re a single 122mm HE shell. Medium IEDs look like 3 122mm shells taped together. Large IEDs appear to be a cluster of 5 152mm shells and huge IEDs are apparently a 500lb bomb.

These obviously increase in destructive potential as they get bigger. In order to gauge potential effects it’s helpful to link IED size to vehicle size. Small IEDs are capable of destroying light vehicles, such as Humvees. Medium IEDs can destroy medium sized vehicles like Bradleys. Large IEDs can destroy tanks, including the Abrams. Huge IEDs are basically large ones with a greater effects radius.

Trigger Mechanism

To go along with size, IEDs come with three different types of trigger: wire, radio and cell.

These have two key characteristics: range and failure rate.

Wired IEDs have a range of 100m and a 10% failure chance.

Radio IEDs have a longer range of 300m, but a 20% failure chance.

Cell IEDs have a range of 600m and a 10% failure chance.

The failure rate represents the chance that the IED malfunctions in some way and doesn’t detonate. If it fails then the word (Malfunction) will appear next to its name when you select it.

Slightly different from failure rate is the susceptibility of radio and cell IEDs to jamming. Some vehicles carry IED jammers that interfere with the trigger signal and prevent the IED from detonating. The key difference between jamming and failure is that jammed IEDs can still detonate, while malfunctioning IEDs are effectively out of action.

It’s not clear how jammers work. From some testing, it looks like they significantly reduce the chance of the ID being triggered: it’s still possible and the longer a target hangs around near an IED the more chances it has to go off, but between the inherent randomness and lack of feedback it’s hard to nail down exactly what’s going on.

Triggerman

Of course, to detonate the IED we need a triggerman. This is a pixeltruppen with an IED trigger in their inventory. The triggers are not differentiated by type. As long as they have an IED trigger, they can set off any IED whether it is wire, radio or cell controlled. This isn’t necessarily realistic, but it is a very helpful simplification in gameplay terms.

It also gives some flexibility or back-up capability on the battlefield: you can have multiple triggermen watching the same IED, one triggerman watching multiple IEDs and move your triggermen about as required.

To detonate an IED, the triggerman needs to be within range of the IED in question, and he needs to be able to see whether there is a target near it. It doesn’t appear that IEDs can be detonated from contact icons, the triggerman has to make the spot himself.

This is obviously a lot more difficult if he is under stress- if he’s under fire or he’s pinned.

IED Procedure

So, that’s all the components to remote controlled IEDs, mechanically in Combat Mission they have to be activated before they can be used.

That at least is very simple: all you need to do is select the IED and give it a ‘Target’ command. If you target the ground, then the IED is ‘Activated’ and the triggerman will set it off when he sees an enemy unit come near.

If you target a specific unit, the triggerman will only try to detonate when that unit reaches the IED.

So there is a little bit of targeting flexibility.

Tactics

Fundamentally though, these and the IED mines are passive weapons. The enemy needs to come to them for them to work. Given that the enemy is not likely to be cooperative, intelligent placement of IEDs is critical. Areas the enemy are likely to travel through or occupy are obvious contenders, especially if chokepoints or confined spaces can be found, but these come with the caveat that they are obvious IED locations the enemy might specifically avoid.

So finding likely but less obvious areas to emplace them is important. In particular, they’re best used in conjunction with other assets. If we think about an ambush, for example, we might be able to predict where enemy troops might take cover and then seed that area with IEDs. Alternatively, the threat of IEDs in obvious chokepoints or areas of dense undergrowth might encourage the enemy to spread out into the open where they will be more vulnerable to small arms fire.

VBIEDS

Finally, we have the VBIED or Vehicle-Borne Improvised Explosive Device. One of the core downsides to the mine type and remotely activated IEDs is that they are immobile: once you’ve set them up in the deployment phase, that’s it, they can’t move. Obviously putting an IED in a vehicle and turning said vehicle into a carbomb allows it to be used in a much more active way.

In functional Combat Mission terms, VBIEDs are essentially huge IEDs in a civilian car: there’s a 500lb bomb in the backseat. There are no activation or triggerman mechanics though. Used as intended, the driver detonates the VBIED when he gets close to the enemy.

Less intentionally, it can go off when it takes fire. Whether that’s because the driver pushes the button, there’s some kind of dead man’s switch or it’s an exercise in sympathetic detonation isn’t clear.

If the driver is killed without the VBIED going off, or he dismounts, then sympathetic detonation is the only way to set it off. You can’t drive it up to a target, get out and remotely detonate it. If the VBIED is intact, you can remount it or get another unit to drive it, in which case it will function as normal. Evidently, everything that makes it work is inside the vehicle.

The trickiest part is actually getting the VBIED to a target. There’s always the risk that it gets pre-detonated on the approach, but a deeper issue in Combat Mission terms is that it can be quite difficult to drive into an enemy unit when playing in turn-based mode, especially if the target is moving.

So they’re best used against static units and conducting some kind of reconnaissance to locate potential targets is absolutely vital. VBIED guided munition, not something you want to be using to hunt for targets. It’s somewhat limited by the necessity to detonate on or near an enemy unit. This means you can’t, for example, target unoccupied buildings or bridges, and that the driver and/or passenger need to make the spot, which can get frustrating in some situations.

Conclusion

That then, is a quick roundup of IEDs as modelled in Combat Mission. The big takeaway is that while they can be a useful asset, they are a weapon of weakness that need a lot of elements to align properly for best effect. They are considerably more difficult to use than conventional weapons.

Hope you all found this one useful, IEDs aren’t the easiest things to get your head around in Combat Mission. If you’d like to see these videos early and support the channel, you can do so via Patreon and Youtube Memberships. Whether you do or not, thanks for watching and I’ll catch you in the next one.