So, now we’ve set up the conditions for your battle, gathered the armies, plotted their lines of march, determined their campaign objectives, and put them on a collision course with each other, it’s time actually write the fighting, right?
Well, not quite.
Before we do that, we have to dip back out into what might be called ‘Operational Planning’ in the context of military theory. This time, however, we won’t be thinking as military planners, but as writers. Just as commanders have to go into a campaign thinking about what they intend to accomplish and how they intend to accomplish it, a writer needs to do the same thing. So, before you start shaping a battle within your story, it’s important to ask yourself some basic questions about your plot and characters: specifically, who does your plot need to win this battle? How? Which characters are involved? And how does this battle affect them? These are important questions to answer, not just when it comes to writing battle scenes, but also any other sort of plot development, so I’m going to go over them real quick.
The most basic question to answer is, of course, who wins? While a wargamer or a writer who is basing their narrative on a simulation (writing an After-Action Report, perhaps) might use that simulation to determine the outcome of a battle, most writers should consider it from the other way around. Who does the story need to win, and how does the story need them to win? When it comes to writing a compelling narrative, the latter is as important as the former, since it shapes the way the battle opens, progresses, and ultimately concludes. An English-led army beats a larger French army at the Battle of Agincourt with a hail of longbow arrows and a bloody melee in the slippery mud. An English-led army beats a larger French army at Waterloo by holding out the morning until it can be reinforced by a Prussian army in the afternoon. While the basic setups and outcomes are the same, the means by which those outcomes are achieved are different, and as a result, make it easier for different types of stories to be told.
Likewise, it’s important to determine which characters are present and how the battle affects them. Your characters, ultimately, are the means by which your audience interacts with your narrative. The audience cares about what happens because (in theory) they care about the characters, and want to know what happens to them. Thus, any suspense derived from a battle’s outcome or conditions generally comes as a result of potential effects on the characters which your audience has an emotional connection to. Audiences do not care about faceless extras on a battlefield – even if they care about the well-being and lives of strangers in real life, the strangers in a narrative are ultimately just mental constructs, which don’t have any of the endearing attributes needed to win an audience member’s empathy unless a writer gives them some. Thus, it becomes important to make sure there are people who your audience cares about involved in the outcome of the battle. That doesn’t necessarily mean characters that you’ve already established have to be physically present, fighting in the action, although that obviously makes things easier since it gives you immediate stakes to pull your audience’s attention (which is to say, they might be wounded or killed). Battles also affect those outside of the fighting – friends and relatives of those in the armies, the populations of the regions the fighting involves, those in the rear areas or the baggage train. If you have established characters in any of these places, then it’s not too difficult to find a way that a battle won or lost might affect them.
Of course, if you’re really confident in your abilities, you can always introduce a new character in the middle of battle. A particularly good writer can introduce a character, make them gain the audience’s empathy, and kill them off in the space of a few sentences. If you think you can do that, then it’s definitely something worth trying, though I wouldn’t necessarily recommend making that the only sort of emotional connection your audience has to the outcome of a battle. After all, if you keep killing off bit characters without affecting any of the “main cast”, your audience will catch on soon enough.
That brings us to the other half of the question: what happens to your characters in this battle? Obviously, you’re expending a lot of time and effort putting all of this together, and your audience is putting a lot of time and effort keeping engaged, if you go through all this trouble to set this battle up without having it meaningfully change anything, then both you and your audience are going to feel cheated. So it’s important to determine what happens to each of your characters: do they lose a limb? Lose a friend? Maybe they find a fortune, or glory, or even die on the field or in the aftermath. The important thing is that there are enough changes to propel the plot forward and advance the development of your characters to justify all of the effort spent on setting this battle up and engaging with it. In return, choosing what happens to your characters in the battle helps you determine how that battle should play out, while also contextualising those character developments. For example, if you want to set a poignant, melancholy mood, you could have a character lose something or someone important while on the winning side. Mark your character out as a hero by setting their actions against the background of a defeat, or even have them turn the tide of the fight themselves. The image which the audience sees is neither just actor or backdrop, but a contrast between the two – and getting that contrast right can lead to some very emotionally powerful moments.
Now, at last, you should have all the fundamentals you need to determine how your battle’s going to go, to determine which troops have to go where and which individual engagements have to be won by which side to make it fit into your story. I’d definitely recommend doing a little research here, especially if you’re going to be writing in a historically-inspired setting. While it’s definitely possible to have fantasy elements change the way your setting’s battles play out, it is important to keep things consistent, and if you’re writing a setting where horses, cannon, pikes, or human beings move and act like they do in our world, then you should probably make sure that they aren’t doing something so beyond belief that they break your audience’s immersion – unless you’re specifically trying to make a point.
Once you’ve set up an outline of how your battle’s going to go, it only becomes a matter of writing it out – which is a lot harder than it sounds. After all, battles are by definition, events where a lot of people do a lot of things at the same time – a scene where hundred or thousands or even millions of individual actors are moving by themselves, or as part of formations. If you were to describe every major action in even a relatively small battle the way you might describe a one-on-one fight, you’d be writing for a lifetime, or more.
Thankfully, you don’t have to do that. Stories, after all, tend to be told from the perspective of their characters, and those perspectives can both serve as illumination, or as a filter, narrowing the field of what the story needs to describe, or pushing out happenings which a given viewpoint doesn’t consider all that important right at that moment. Much like in a more individual fight, characters tend to be directly focused on what affects them in the immediate term – which is what you as a writer should be describing through them. Of course, in the case of a large scale battle, this is determined not just by that character’s immediate surroundings, but also by their level of responsibility and position within the belligerent armies, and on the field of battle itself.
Take, for example, the perspective of the common soldier. From their eyes, you can only describe what they see, and from the ground level, they can’t see much. They probably won’t know their army commander’s plan for directing the battle, they certainly won’t know the enemy’s plans. They probably won’t even know the general arrangement of the contending armies, or have any meaningful view of how the battle as a whole develops. Before battle is joined, they might be able to catch a glimpse of what the people around them are doing. Once they’re in the fighting, they’ll be almost certainly focused on the enemy in front of them, their peers beside them, and their immediate superior’s orders. Their perspective of the fight will be extremely narrow, though what they can see will very likely be up close and personal. The result is perspective which blots out the wider scope of how the battle develops, and leaves them ignorant of most of the movements of the battle itself, until it affects them, their immediate comrades, or their enemies directly.
On the other end of the scale, take the commanders of the armies involved. While there definitely are historical cases where generals led from the front, these tended to be relatively small scale or simple battles. To coordinate a large engagement with many moving parts, a general would often have to stay separate from the fighting, either entirely, or until the moment where their presence at one point of the field would justify charging in personally. This means that for most of the battle, the general would be away from the fighting, watching things play out from a vantage point where they can see more or less what’s going on. In a time before instant communication, this means most of their knowledge of the details of the ongoing engagement would be limited to reports from runners and couriers, which might be minutes or even hours out of date. Likewise, their ability to command would be limited to the use of the same instruments, which could lead to orders being garbled, delayed, or not received at all. In that sense, the perspective of an army commander could be just as limited as that of a common soldier, but in a distinctly different way. Instead of focusing tightly on the fight around them, they have to take stock of the whole battle, with no time or effort to consider individual combat or the details of any single point of contact, unless they choose to wade in personally, at which point their perspective shrinks to that of an individual.
There’s levels between these two extremes, of course. While the sort of complex staff appointments and rank systems we’re familiar with in our own world’s militaries tend to be a hallmark of the sort of professional fighting forces which dominate our own present, any army of sufficient size requires a hierarchy. No single person can command tens of thousands of soldiers by themselves. They need subordinates to command, who in turn pass their orders on to their own subordinates, with the officers at each level only dealing with a relative handful of individuals, in a number small enough to effectively manage. As a result, the perspectives of each of these sub-commanders is also limited to the level above and below them. A low-level commander, like a squad leader, might be focused on the well-being of those soldiers immediately under their command, and perhaps that of their immediate commander (the equivalent of a platoon or company commander). Likewise, a relatively high ranking sub-commander would be focused on the actions of their immediate subordinates and superiors, may may not have any insight into the actual soldier-to-soldier fighting at all.
There’s obviously a lot more detail to get in to, especially when it comes to things like particular types of battles using particular types of weapons, but that subject would require an entire addendum on its own. In the meantime, when it comes to more general guidelines, this should be enough to get you started, at the very least.