Mass Versus Mobility (part 2)

An army should always be so distributed that its parts can aid each other and combine to produce the maximum possible concentration of force at one place, while the minimum force necessary is used elsewhere to prepare the success of the concentration.
- Sir Basil H. Liddel-Hart

Why hasn't this been said elsewhere?

As I said at the beginning of this site, I'm a relatively new 40k player. I started playing in August, 2004. Since then, I've averaged at least one game/week, often more. But that's far less than a lot of other players. Many of whom write things on the internet. I'm not so arrogant (I hope) as to think that in the 20+ years that this game has existed, no one else has thought of this. So why can't I find information about the idea online?

My first thought is that the idea is so simple as to not warrant writing elsewhere. But, I don't agree with that, because if it was so simple, so many players wouldn't screw it up. So that's not it.

So, the second thought is that maybe it is out there, but in a different form. And sure enough, that's the case. Most of the 40k websites I've read have a narrow focus. They're very focused on armies, to the exclusion of generalist strategies. But, if you look around, there are sites that are dedicated to specific armies, which espouse the same strategic concepts that I've put forth in general terms.

In fact, several armies have rules that even encourage correct play. I think it's worth a few paragraphs to examine these.


Marines are the most generic of armies. They're likely to be more mobile than heavily mass-oriented armies, while more massive than heavily mobility-oriented armies. Their stats support this generalist form of play.

Still, some marine variants are heavily skewed in one direction or another. Ravenwing, for example, is one of the most mobile forces in the game. Every unit at their disposal is capable of a 24 inch move. And, checking one of the more comprehensive Dark Angel's sites on the net, Fortress Unforgiven, reveals that standard Ravenwing Tactics are solidly mobile-army tactics.


Orks (not Kult of Speed) are a mass-oriented army. Orks even have rules that make playing Mass-oriented strategies more favorable. Mob Rules tend to keep the ork forces together. Rules for gretchin make it favorable to keep your gretchin with your orks. Large unit sizes, and bonuses for having large units also tend to keep most of an ork army's points close together. Even when orks lose their leadership checks, they can group back up with other orks, again tending to make it beneficial to keep the orks close together for optimal effectiveness.


Necrons are another mass oriented army, and also have rules that make it beneficial to keep units together. The traditional phalanx tactic works not just because of the Necron's special rules, but also because they force the Necron player to play correctly as a Mass army. Keep your units within so many inches of your other units isn't just for We'll Be Back rolls, it's so that each unit can support each other properly.


The new Tyranid codex is deceptive at first read. The number of Fleet units, and ability to move through cover seems, at first glance, to indicate that tyranids are designed to be a mobile army. But, this is misleading. The new Tyranid army is designed to be played as a Mass army.

First, Fleet moves are not all that mobile. Any mechanized force (mounted in transports) can out-move fleet moves, as 12 guaranteed inches is more than 6 inches + d6 inches. Secondly, while the Tyranids may be fast, they're not especially maneuverable. A combination of large unit sizes, and slow-moving synapse nodes mean that while they can achive fast vertical board crossings, they suffer if they have to redirect their initial charge horizontally. Finally, they have a significant number of advantages if they stay together (within range of their synapse creatures), and numerous disadvantages if they stray too far apart.

Tyranids seek to win wars of attrition - a feature of predominantly mass-oriented armies. They throw waves and waves of small creatures at the enemy, hoping to drag them down with numbers, or hold them in place long enough for the big creatures to show up. All of these factors combine to indicate that the bugs favor the Mass approach, even though they have some speed.

Imperial Guard

Imperial guard are another army that gets rules designed to encourage their generals to keep their troops together. Their Communication links, giving Leadership bonuses to units near their commanders, is an example of a rule that rewards sticking together.


The Tau are able to make a solid mass army, with lots and lots of guns. They're also able to make a fairly mobile mechanized army. Not surprisingly, Tau tactics have evolved separately for these two types of forces.

Static (massed) Tau stresses buying lots of guns and bodies. 72 Firewarriors is not unheard of, and overlapping fields of fire is the stereotypical Tau deployment. A typical Mass deployment.

On the other hand, Mechanized Tau, as described at the Mechanized Tau Tactica site, instructs players in the virtues of the mobile strategies; isolate and destroy, avoiding head-to-head confrontation, and the use of terrain to avoid unfavorable engagements.


Eldar are another army that can go in either direction. A massed eldar army can benefit greatly from the abilities of Farseers to cast spells on any unit within so many inches. This encourages the deployment of at least two units and a farseer within relatively close proximity, so that the farseer can choose to guide the appropriate squad each turn.

They can also go highly mobile with their mechanized force, with all sorts of vehicle upgrades allowing them shoot on the move, making good use of terrain and pick off isolated squads with ease.

Where the Narrow Approach Fails

Still, these websites, because of their narrow focus, encourage incorrect play in the cases where the army they focus on ends up playing the opposite role.

For instance, the Mechanized Tau concept, as described in the link above, goes to great lengths to explain how to use the Mechanized Tau as a Mobile army. However, it's far from the most mobile force out there, and as such, will be forced to play the role of the Mass army when such matchups occur. Afterall, the mobility of a Tau Devilfish looks distinctly underwhelming when compared to an Eldar Waveserpent, capable of mounting twin-linked brightlance or starcannon.

If the Mechanized Tau player attempts to simply follow the instructions found on his tactics site, he will find that it is the Eldar player who ends up out maneuvering him, picking off his isolated units. And he will wonder, "what did I do wrong, I followed the advice on my website, and I got owned."

This is where the generalist view of strategy comes in. We can design our army, hoping to be more mobile, or more massive, only to encounter a more extreme army. When this happens, we have to identify it, and play the other role as well as we can with what we have. While it may not be the way we planned to play our army, to play against the role you end up with is to invite defeat.

Such is also the case when roles change mid-game. A mechanized army may find that its transports have been destroyed, and its foot troops are now left to walk. Their best chance of survival now depends on sticking together to form some sort of a mass front, for if they remain separate, they will become easy pickings for any of their opponent's faster units that sense an opportunity.