Monday 17 October 2016

Mass combat rules for 5E - first considerations

For our 5E campaign I was looking for mass-combat rules and was happy to find exactly this on the Wizards of the Coast site (here). However, I have some problems with these rules. The main ones being, it is still one roll per figure (representing 10 individuals), rather than per unit, and thus speeding things up only by a factor of 10. In my view this makes it suitable for skirmishes, but not for large-scale battles.

'Battle of Grunwald' by Jan Matejko (1878)

The other thing is that individuals are treated differently from units, which basically means that heroes/PC's can do things under these rules, they cannot under the rules of individual combat. Dan, of 'Delta's D&D Hotspot'-fame, has written a nice article on the short-comings of this rule set and he identifies even more weak points.

Dan's Book of War


He also wrote the awesome 'Book of War' some years ago. This little booklet contains a very simple, yet elegant and complete, system for playing out large-scale battles within the OD&D system. It is fun, fast, and exciting until the very last pieces on the board. I highly recommend it as stand-alone game and as an extension to your OD&D or AD&D campaign.

One of the nice features of his rule system is that it scales with the individual combat system, unlike many other mass-combat systems. This means that it does not matter if you play out the combat by these rules or by the individual combat rules of OD&D; on average both yield to the same result! This is clearly not the case for the 5E mass-combat rules as presented by WotC.

Would it not be nice if there was such a thing as the Book of War, but then for 5E? I know that I would be interested!

And this is exactly what the next few posts will be about; developing a mass-combat rule set for 5E that scales with the individual rules for combat.

The first, obvious, question to ask is 'Can we use Book of War for 5E as is?'

To answer this question we have to look a bit deeper into the workings of the Book of War.

Core principles of the Book of War


The first thing this the rule system does is granulating the individual combat rules by changing the scales of things: 1 figure represents 10 individuals, 1 round equals 30 seconds (equaling 3 individual rounds of each 10 seconds), and 1 square is 20 feet (in stead of 5 feet as is the case for individual combat).

The combat itself consists of an attack roll (with one die per attacking figure) and for every success one hit is applied to the target unit. A hit equals 1 HD of damage and thus each hit removes one 1-HD figure or deals 1 HD of damage to a multiple-HD figure. The attack roll is done with d6s as opposed to d20s for individual combat, which basically means that AC is now 3 times as coarse.

Since AC has hardly changed with different editions of D&D, we can use the same principle within 5E; just divide AC by three (rounding down), and that is the number you need to roll for a hit on a d6.

So far, so good.

But then things get complicated. As said above, a single hit in OD&D means 1d6 damage but also a single HD means 1d6 hp, and thus a hit is equivalent to 1 HD. That is why damage and hit points are so nicely abstracted away in Dan's rule set.

Within 5E, however, there is no concept of HD, or rather hit points are determined by hit dice ranging from d6 (wizard) to d12 (barbarian) and also weapons deal a variable amount of damage per hit ranging from d4 (club) to 2d6 (greatsword). In other words, a single hit cannot directly be linked to a single HD as both the damage die and the hit die are variable. Even worse, attribute modifiers play an important role in 5E, complicating the situation even more.

Towards a 5E mass battle system


To solve this, the hit points must be normalized to construct an equivalent of HD. In principle you are free to choose any norm, but I think it is sensible to choose it such that a single hit corresponds to the removal of a single low-HD figure (what used to be a 1 HD monster in earlier versions of D&D). This means that we have to norm the damage as well (but not necessarily the same norm as HD because we can stretch or shorten the time scale).

So, in short, the Book of War rule set cannot directly be applied to 5E, but with some normalization of hit points and damage dice, we might be able to construct a rule set very much in line with it.

What these norms sensibly should be will be the topic of upcoming posts.