One of the old rules of war is that “you don’t attack the medics”. In fact, traditionally, it wasn’t uncommon to call a temporary truce in the middle of battles to let everyone recover their wounded.
Yet human beings are awfully pragmatic when it comes to fighting each other. They may get sentimental about creatures that present no real threat, but when it comes to survival, pragmatism is bred into the bone. Why would they do that?
It’s actually simple enough. The old rule of thumb was that a wounded opponent was BETTER for your side than a dead one. A dead man was permanently out of action, yes – but his friends just took anything useful off the corpse and pressed ahead. Sometimes they were even inspired to make greater efforts rather than falling back.
A seriously wounded man was out of action – and so was whoever took him and his gear to the rear, where he would continue to soak up his sides resources for an indefinite period of weeks or months. He’d require food, and water, and transport, and the attentions of a healer, and it was quite likely that he would never recover enough to fight again. If he died, everything that the enemy had invested in him since he was wounded was a profit for you. If he didn’t fully recover, he’d have to be shipped home – draining even more resources from the war effort. He might not even recover enough to work, in which case he would become a lifetime drain on the enemies resources.
On the average – and often by a broad margin – a seriously wounded opponent was a bigger victory for your side than a dead opponent. It was very good for your side to let the enemy recover their wounded – and once you gave the enemy that option, they had little choice but to take it. If one side had a chance to recover their wounded, and did not do so, that side’s troop morale would go to hell. On the other hand, if you kept the enemy from recovering their wounded, their morale might well rise.
You didn’t attack the enemy medics or hospitals; the more resources the enemy had tied up in supporting such institutions, and the probably-useless men they contained, the better it was for you.
The medics, in their own self-interest, tended to treat everyone – although enemy soldiers usually got a lower priority. After all, that gave individual enemy soldiers, as well as the tacticians, a good reason not to attack them. To any individual soldier the medics were harmless and helpful, no matter how much the strategic commanders might secretly wish them all dead.
In gaming, however, the cry often becomes “Geek the Healer!”.
Despite the attitudes of some of my ex-military players, that’s not “wrong”. That’s because, in general, wounds and healing in games isn’t much like wounds and healing in reality.
In reality, wounds are messy, often become infected, usually result in at least some disability, and recovery takes a long time. In games, wounds tend to heal quickly, cleanly, and completely. That’s because it’s not much fun to play a seriously crippled character, and minor penalties that don’t come up very often are far more trouble to keep track of than they’re worth.
That means that wounded enemies may well be back in action for the next battle – and that few or none of them will become a burden to the enemy. Allowing the medics to treat the enemy wounded becomes a lot more problematic – and the enemies medics become a net benefit to their side, instead of a drain on their resources, making them viable targets.
In quite a lot of worlds, “first aid”, magic, psychic powers, or other options are sufficient to get a casualty up and fighting again within minutes.
In this case, the priorities shift completely. Healers become high-priority targets – and if one of them treats a wounded enemy, it had better be because they’re wanted for interrogation, enslavement, or a formal execution later on; otherwise it’s stabbing their own side in the back. Any sensible opponent will make sure that anyone who goes down stays down unless there’s some really good reason to risk them getting up again – and, even then, a lot of the common troops will opt to make sure that enemy wounded are really dead no matter what their orders are. Trying to take prisoners adds to their risks quite substantially and profits them very little no matter what their commander has in mind.
In many settings, opponents are unlikely to even be of the same species – which makes options like capture, enslavement, and integration into the victor’s civilization pretty much unusable. That kind of thing is simply storing up trouble for your grandchildren. Like it or not, when two species are competing for the same resources and living space, sooner or later, one pushes out the other one unless – perhaps – the local gods (or nigh-omnipotent aliens or whatever the local equivalent is) enforce some sort of “balance”. Even then, that’s likely to result in perpetual warfare. The war of extermination – an attempt at total genocide – is the sensible, rational, default position for wars against other species. Anything less is betraying the next generation of your species. It’s kill them now, or know that they’ll be killing your children later.
The only really stable alliances are either going to be maintained by massive external threats or are going to be between wildly disparate species that aren’t in direct competition with each other. And no, this doesn’t mean that those classical human-elven alliances are out of the question; in most worlds humans and elves are fertile with each other and produce fertile offspring – which means that they are minor variants on the same species, not competing species. You wouldn’t expect a massive human-elven war until no one else is left, and perhaps not even then; since both species variants have different advantages, you might see an equilibrium.
When your enemy is almost certainly out to kill, and to make sure of those kills, quite a lot of the more complex considerations of games theory go out the window – and the tactics can get pretty basic.
For a start, you:
Fight to kill, and assume that your enemies are doing the same.
Eliminate effective healers (anyone who can bring opponents back from the dead is a top priority) and high-damage low-defense targets first. After that, you want leaders and the support staff; once the more durable targets are isolated they can be pulled down at leisure.
Make sure that any opponent who goes down is dead.
Fall back and get out if the battle is going against you. If you can’t, you might as well fight to the death; surrender is not really an option when it just means “death slightly delayed to allow for interrogation or being shown off”.
Always fall back on defensive positions (if possible) and call for backup whether or not any is available. If it is available, having overwhelming force on your side keeps down your casualties and helps ensure that no opponents escape. If it’s not, well, the enemy is more likely to make mistakes if they’re acting on false information – and that’s usually good for you.
Try and kill as many retreating opponents as possible while making sure that you don’t follow a retreating opponent into an ambush.
Always remember that, if you’re fighting another species and can wipe out the women and children, you’re most of the way to victory.
Always keep guards and scouts out; it’s better to lose a scout than for everyone to get killed.
Never assume that an area is secure or peaceful. In wars of extermination, such unguarded areas make the very best targets.
There are, of course, many, many, MANY volumes on strategy and tactics out there – but those are some basics that almost any sapient opponent should know and pay attention to. The parties opponents in a role playing game generally want to live just as much as the player characters do, and will take precautions, plan ahead, and use the best tactics they can come up with within the limits of their intelligence to make sure that they’re the ones that do so. Don’t hand out boring and unearned victories. Winning is a lot more fun when you have to work for it.