One of the reasons that I turn critical eye towards the battle scenes in Fantasy novels is that I really enjoy wargaming. Wargaming is a tabletop game where each player fields a little army and attempts to overcome the other in battle. My game of choice at the moment is Warmachine/Hordes by privateer press. Hordes is especially fun with the giant warbeasts having this Pokemon meets Heavy Metal Magazine feeling to them. I enjoy painting and assembling the little figures; I find the craft aspect very relaxing. It also takes me away from the computer, which is very important when I am deep in revisions and spend almost all of available time glued to the keyboard.
Playing wargames gives you a sense of strange and exotic tactics. History and actual military theory give a better understanding of warfare, logistics, and tactics but wargaming puts you in the commanders chair and lets you game the outcome of your choices. It is an interesting experience. I feel it is one of the best ways for a Fantasy writer to experiment with introducing new elements to the battlefields and seeing how they could effect the tactics and outcomes of battles in your written work. Here are a few ways wargaming can help you understand how Fantasy elements can change warfare.
1) Exotic Powers = Exotic Tactics: Each wargame has a set of rules. Players will try to exploit the rules to maximize their advantages, often pulling off strange and amusing manoeuvres to give them an advantage over their opponent. In realistic wargames these exploits are often very close to real tactics. Snipers try to find vantage points that dominate the battle and so on. The moment you add unusual abilities to a wargame you start to see unusual tactics develop around those abilities and how players try to counter them. In Warmachine/Hordes several armies can harvest the souls of dead allies/enemies which can lead to all sorts of strange denial games where a players try to position soul collectors to maximize gain, deny the enemy, and so on. It adds an interesting level of detail, especially watching how others might exploit the element you introduce.
2) Visualization: Setting up a little army and gaming out your new fantasy element, be it a strange spell or wierd creature in the battle helps give you better a sense of the impact it might have.
3) Creating Consistency and Definition: Describing a fantasy element in such a way that the reader is enticed is good. However, it is also important to define how the element works and be consistent in your uses of it. If a magical sword can cut through a steel door in one scene and bounces off a shield in another, you might have some explaining to do. Wargaming forces you to create rules for your creation which will give it more definition in your mind.
If I wanted to see how a giant with an aura that freezes everything around it might effect warfare I would first write up a brief description of this creature and its powers. Then I would check and see if Warmachine/Hordes had a figure with similar powers. It turns out the Trollbloods army has a Winter Troll that has a set of abilities similar to what I’m looking for. Enemies that get too close to or strike the Winter Troll can become frozen. Its a good starting point. Sadly the WinterTroll does not quite seem large or powerful enough to represent a mighty colossus striding the battlefield. So I take the powers of the Frost troll and tack them on to the stats of a bigger, stronger model like Mulg the Ancient, a gigantic troll (removing some of Mulg’s powers as I see fit). I can then fool around with my creation in a game I am familiar with and see how it distorts the battle field and how people react to it.
But I recognize that you might not wargame. In truth I just wanted to chat about one of my hobbies and litter my blog with cool pictures. So here are a simple set of considerations that I use when introducing a Fantasy Element to warfare. I will use Dragons as an example, to illustrate each consideration.
1) Power: how dominant is the element you have introduced. Power is the easiest consideration for a writer. You generally know how powerful you want the element to be or can get an idea of the power by sitting down and dissecting you descriptions of it. Keep in mind that power is relative. The power level of some fantasy elements are subtler than others. Summoning fog might seem like a weak power compare to throwing fireballs, but quite a few battles have been won by armies that use fog to ambush or gain a position advantage over their enemies.
In most fantasy worlds Dragons are extremely powerful. They have fiery breath that can kill many men. They have thick scales that make them hard to hurt. They are huge and strong. They can fly, which gives them a mobility advantage. Yeah, definitely powerful. If introduced to a medieval setting, the Dragon would dominate.
2) Versatility: Versatility is a little trickier than power. Does the element you are introducing offer a wide array of possibilities and advantages?
Dragons are fairly versatile. They offer advantages in mobility as well as brute power. The can act as mounts for other creatures. Most Fantasy dragons are intelligent as well, which is another form of versatility. They offer significant advantages in attack, scouting, transportation, and several options rarely seen in other units in a basic medieval battlefield. Having a wider variety of Dragons or Dragons that can use magic would increase the versatility consideration of this element.
3) Rarity: is it common, unique, or somewhere in between. If an element is rare in your world, people are less likely to be able to identify or react to it, or might just not consider it worthwhile. If an element is rare, it could mean that only one side of a conflict has access to it. If it is common then everyone will know its weaknesses and are more likely to prepare for it.
Dragons are usually fairly rare. I could decide to make them common through breeding programs or even make it so than only one nation controls them. If the were too common then I would have to come up with a reason why they don’t displace all the races in my world with their scaly magnificence.
4) Limitations: Does the element you introduce have any significant weaknesses, drawbacks, vulnerabilities or anything else that might limit it.
Dragons are usually greedy and paranoid, which makes them less likely to band together. If their greed is compulsive, it might make finding allies difficult. They are large, so might have trouble getting into small areas and require lots of food which may lend new significance to supply lines or even create atrocities as they feed on enemy soldiers. A low birthrate might make them paranoid about dying.
5) Reactions: This is the most difficult and most important consideration. How will everyone react to the element? If an element is extremely rare, people might not even bother to prepare for it. However if it is both powerful and fairly common it will warp the battlefield. Things to consider are weapons designed to overcome strengths or exploit weaknesses, how fortifications and supply are effected, and what sort of tactics will take advantage of the element or be used against it.
Since Dragons can fly, missile weapons are a good answer to them. Heavier missile weapons would be required to get through their heavy armour. Wings might be especially vulnerable to ballista shots and such. Since Dragons are huge, breathe fire, and fly Fortifications designed to counter them would have to be stronger, flame resistant, and have some form of aerial defence. Dragons are great at raiding supply lines, but also require a fair bit of food, this could become important elements in your battles.
Bonus: Interactions (Combos!) Consider how will one element change another or enhance another.
Gunpowder is explodes when exposed to fire. Dragons breathe fire. This means that cannons are vulnerable to dragon attacks. It could also lead to all sorts of shennanigans with Dragon riders dropping powder bombs for the Dragons to light up.
These are just some simple guidelines. In the end them important thing is to sit down and consider how each element could change the battlefield and how the principle actors that you have created with act and react in accordance with that.