Medieval military tactics, given the presence of a single invincible champion in every nation's army

Question

The setting is low fantasy medieval. Magic (and other supernatural things) belong exclusively to the realms of the gods, and are not for mortal beings to wield. However, there is one major exception.

Each and every recognized kingdom in the world has a single major patron deity who watches over it. They may have other lesser minor deities as part of their pantheon, absorbed from conquered cultures, but the most important thing is the blessing of the patron deity.

Each kingdom has possession of a suit of divine armor and a matching divine sword, bestowed upon them by their patron deity. Anyone is capable of wearing and wielding these artifacts of power, but it requires an uninterrupted hour and a team of high-ranking priests of that deity to perform the prerequisite donning rituals in a sanctified location like a church or cathedral. Part of the donning ritual includes the armor and sword being magically resized to suit the kingdom's chosen champion.

The armor has the appearance of a full suit of medieval plate mail, but with the metal taking on a shining golden color, rather than having the appearance of steel. The sword is generally a knightly arming sword with a similar appearance. Exact styles vary, and are up to the individual patron deity.

When successfully donned, the inside of the armor is supernaturally connected to the patron deity's private god-realm. The chosen champion is technically no longer inside the armor at all, although they appear to be. They are fully able to control the armor as if they were wearing it, and have the same vision, hearing, and nearly the sense of touch as if they were wearing mundane armor.

The effects of the divine armor are as follows:

• The armor itself is absolutely invulnerable to damage in any form. Projectiles cannot pierce it, blunt impact cannot dent it, fire cannot scorch it, etc.
• Light and sound are transferred to the wearer's senses normally.
• Force only to a non-harmful degree is transferred to the wearer's senses. This means they can lift an object and feel its heft, touch and feel solid objects, and so on, but will never be harmed by a mace to the head. The impact will be reduced in strength when transferred, so the wearer would feel it only dully.
• The wearer is aware of the size and shape of the armor, but does not feel the weight of the armor. It is sort of like wearing armor made of styrofoam or cardboard: all bulk and no weight.
• Temperature and particulates are not transferred. The wearer always enjoys breathing and existing in the pure and comfortable air of the god-realm, which means they can stroll through clouds of poisonous smoke and burning buildings with nary a care. This has the side effect of cutting off the user's sense of smell and taste.
• Nothing else can enter the armor with the user unless it too goes through the lengthy prerequisite rituals, and each patron deity's is unique. That means no daggers through the eye holes or armpit slots. They are simply blocked by divine force.
• Things do not stick to the armor. That means tar, blood, and boiling oil will just slide right off onto the ground with no residue, leaving the armor always impeccably clean.
• The armor constantly glows with golden light. This is sufficient to see by in an otherwise lightless place. You can easily see a chosen champion from a mile away in any direction, especially at night.
• Assume bodily waste products are handled automagically without the wearer needing to remove the armor. I don't want to dwell on this topic.

The effects of the divine sword are as follows:

• It is just as indestructible as the armor.
• It can be commanded to instantly return to the wielder's hand, so it cannot be lost or disarmed.
• It is razor-sharp and never loses its edge. Furthermore, any material with which it comes in contact is temporarily magically softened, reducing the required force to cut through that material. Mundane steel armor could be sliced through as if it were made of leather, leather armor could be cut through as if it were simple clothing, and so on. With a little elbow grease, it wouldn't be impossible for the wielder to carve their own path clean through a solid stone wall with just human effort and their sword.
• When striking at a living foe, the sword shifts itself (and the wielder's body) to actively target the enemy's vital points. The vast majority of injuries caused by this weapon are therefore fatal, and typically fatal in a single blow. It would be extremely difficult to only lose a limb to this weapon.

Between these two pieces of equipment, the chosen champion of a kingdom can be considered essentially invincible.

However, there are a few important things to note:

• The champion is still human inside all that divine power. They will still experience stress, can be tricked, etc.
• One person, no matter how invincible, is still just one person. A group of enemies can split up and the champion is only physically capable of pursuing one of them.
• The champion still becomes hungry and thirsty at a normal rate. Food and beverages can be supplied as part of the donning rituals in order to allow the champion to later consume them while still wearing the armor. Further rituals can additionally be performed after the fact for this purpose as well. Otherwise, the champion must remove the armor first, which requires a full donning ritual to get back on. This can make participation in lengthy campaigns difficult.
• The champion still becomes tired at a normal rate for the strenuous exercise they are doing. This is partially alleviated by the weightlessness of the armor, but combat is still a tiring activity. They can also comfortably sleep in the armor if they so choose, as their real body is able to relax in their patron's god-realm. (The armor won't stop glowing though.)
• The champion is not protected from very loud noises or bright lights shined into their eyes.
• The champion can be trapped in something like a deep hole, which doesn't rely on direct harm and can't be easily escaped by cutting through something.
• If the divine sword of one kingdom's deity strikes the divine armor of another kingdom's deity, both champions are instantly transported back to the location they most recently performed the donning rituals. This is part of the treaty of the gods, agreeing not to use divine power to directly combat each other.
• If the champion who is wearing the armor and wielding the sword dies, e.g. by dehydration after sitting in a pitfall trap for a while, the corpse and divine artifacts are transported together back to the previous donning ritual location in the same manner as above.

So the question is:

Given each kingdom is always able to field one single incredibly powerful individual, whose supernatural capabilities and limitations are common knowledge, what would be the prevailing tactics in a war between two kingdoms, assuming neither side has any other significant advantages or disadvantages?

In other words, how would rational kings with vast resources and armies of mundane soldiers tactically make most effective use of their single invincible champion, while minimizing the impact of the enemy kingdom's champion?

Edit: While I appreciate the strategic insights, I am really looking for tactics, not grand strategy. That means I am trying to find an answer to things like:

• What kind of supplies/armaments/formations/other tricks might a medieval army bring to a battlefield, in order to best deal with the enemy possibly having an invincible champion on the other side? i.e. It is common knowledge that the enemy's champion is unbeatable in direct combat, but can be outmaneuvered and possibly trapped. What are effective ways to do this?
• What kind of supplies/armaments/formations/other tricks might a medieval army bring to a battlefield in order to best support their own invincible champion if they have chosen to deploy theirs? i.e. How can our side best protect our own champion from being outmaneuvered and possibly trapped?

Answer 1

Dealing with such a foe from a "mortal's" point of view can be done with a long list of "tricks" which play to the weaknesses of the divine champion. Here are some examples:

• Unstable footing:
  • Quicksand: Just because they don't feel the weight, doesn't actually mean that they weigh less. Even if the champion's breathing or movement isn't inhibited, being stuck in quicksand with zero visibility and ending up deep underground is not a fun way to go out
  • Pitfall traps: Digging a hole and putting fake terrain over it is one of the oldest tricks in the book
  • Mud pits: Similar to quicksand traps
  • Budget construction: Because someone with full plate and a divine sword is heavier than your leather-clad archer, it should be easy to construct forts or bridges which can't hold the weight of a champion. Build a bridge over a ravine or a river that regular folks can cross but isn't strong enough for full platemail people
• Too many traps:
  • Nets: The divine sword can cut a single net, but can it cut dozens? hundreds? Even if the sword instantly slices nets, if enough soldiers throw them, then the champion will eventually simply be buried under a mass of nets. As far as you described, their strength is not increased so they can't gain any momentum to swing the sword with.
  • More weight: every solider carries a couple heavy rocks or bags of sand. Once the champion is pinned, they all empty their sand and throw their rocks. Once the champion is buried beneath sand and rocks, they can't really move, and even if they do, sand just refills the gaps. Then they can simply keep heaping things and dirt on top of the champion until they die of dehydration or starvation.
• Nautical based:
  • Watery grave: If the champion falls into water, like the ocean, they would sink to the bottom and have to walk their way home. Many parts of the ocean are so deep and treacherous that even with infinite stamina and endurance, it wouldn't be possible to escape before succumbing to dehydration or starvation
  • Rivers: Throw the champion into a river and let them be washed away or stuck in the bottom, slowly sinking into the constricting muck and silt.
• Light and sound:
  • Archimedes' Death Ray: Give each solider a highly reflective shield and use the sun to blind champions. Alternatively, build large parabolic reflectors to roast some eyeballs
  • Cause a large explosion (idk if this is possible in your setting) and use the soundwave to render the champion deaf.
• Psychological approach (aka dark shit)
  • Classic villain: The champion may be super powered but is their family? How about their friends? Blackmail them into obeying your wishes
  • Depending on the cultural norms, deploy soldiers that the champion wouldn't want to kill like children or women or the elderly
  • Attempt to traumatize the champion by preforming war crimes or other heinous acts
• Rouge things
  • Poison the champion with a delayed fuse poison so they only start feeling sick or seeing hallucinations a day or so after they've injected the poison and are mid-battlefield.
  • Assassinate priests or whoever required to don and doff the armor
  • Get the champion addicted to a certain substance so they start suffering from withdraw if they don't get their fix every x hours.
• Misc.
  • Attack the champion at range, use hot air balloons or airships to drop things on them or use bows and ballistic weapons to bury them in stuff. They can only throw their sword so far
  • Get the champion lost. With their small visors and limited peripheral vision, they presumably don't have excellent spatial awareness and luring them into a maze, confusing forest, cave system, or other could keep them trapped for days
  • Surprise attacks and distributed attacks. The champion can only be in one place at a time.

Answer 2

Form alliances

There are two problems with using these warriors for offense. The first is that the warrior is rendered neutral by the presence of an enemy warrior. That is, your warrior is completely useless if the opposing army can deploy their warrior to counter yours. Furthermore, on the off chance you can trick your enemies and deploy your warrior deep in enemy territory without them being able to attack you, this renders you susceptible to enemy kingdoms going after you. In other words, the presence of these warriors is similar to a 'capture the flag' game, except it's a one on one.

Yes, there are problem with long term deployment, except their really isn't. If you can use the ritual to supply the champion with a large amount of food from the get-go, and the champion can sleep in said armor, he's fine. (I'm not sure about waste matter since you didn't mention that, but I'm assuming it'll be taken care of.) Also, the ability to cut through things with the sword means that the user can effectively tunnel through solid rock, so plenty of places to sleep in safety, and the champion can just tunnel underneath an enemy castle given enough time. Also, keeping track of enemy champions in a low-fantasy setting isn't going to be possible 100%.

That being the case, there's only one rational thing to do - form alliances. With more champions than your opponents, you posses a distinct advantage. Your side can have one champion 'on guard' and one champion 'attacking'. In fact, what will probably happen is a series of feints and countermoves between various factions allying with each other for advantages while planning to betray each other.

Answer 3

Rational Kings will adhere to the time honoree wisdom that ‘amateurs talk about tactics, while professionals talk about logistics.’

They’ll focus on how to use their super-soldier to maximize the damage to their opponent’s infrastructure while minimizing the risk to their own infrastructure. If they can destroy the other guys capacity to feed their people, make weapons, and communicate with their troops, while preserving their logistics then their opponents will implode under social forces of their own societies.

How do the achieve this? One tool is game theory. It provides a solid mathematically model for analyzing gain and loss in conflict. Reducing this notion to its simplest, and thereby least accurate, terms, the conflict could be modeled as a grid of places they could attack, and places they could be attacked at. The model also includes the probability that the super-soldier is part of the attacking force or defending force. Each of these attack and defend options has a gain and loss associated with it — gain being maximized if your super-soldier is present and loss maximized if the opponents super-soldier is present.

If both sides deploy their super-soldiers randomly then there will be a predictable outcome of the conflict. If one side determines a predictable pattern in how the opponent deploys their super soldier, then they can gain the advantage by deploying their soldier were it will do most harm to the enemy and maximum protection to themselves.

Answer 4

Nets and traps. Your army would have dedicated squads armed with weighted nets and long spears and poles. They would move in to entangle and trap the enemy champion who would use his sword to cut through the nets but get more and more entangled until finally they are able to pin him down and restrain his arm just leaving the sword waving around pointlessly.

They would then pile rocks on top of him until he is no longer able to move and just leave him there until he dies of dehydration or starvation.

Answer 5

Kill the priests and steal the opposing divine equipment

Without high-level priests or ritual sites, there can be no donning ritual and divine equipment becomes useless. They are the most vulnerable part of the supply chain feeding the usage of divine champions.

Thus, destroying these enemy assets becomes the most important military objective. Until this is done, actions by the armies in the field can only be of secondary importance, as no objective in the field can really compare to crippling enemy divine ability. Spies and assassins would be your primary weapon, to track down and eliminate all enemy priests, and survey/sabotage/destroy ritual sites.

The spies also enable you to track down the last donning location used. If your army can entrap the opposing divine champion (in a hole or something), then you can proceed to use your own divine champion to secure the enemy donning site. Afterwards, just let their champion starve to death and watch the equipment teleport into your hands.

The same can be accomplished by inserting double agents into enemy society to train as priests, so that they may someday have a chance to steal the divine items.

Answer 6

Alliances would naturally be a smart course of action, but since that answer is given, I'll go with another couple aspect (especially considering betrayal in an alliance).

1. Non-lethal forms of warfare develop.
2. Considerable research will go in to developing decoy armor sets

For (1) let's consider that no weapon a traditional soldier can wield will kill the champion. But rendering the champion useless has potential. As you pointed out, deep holes could work. Maybe things that entangle not based on sticking (ropes, etc). If your traditional soldiers can incapacitate the opposing hero, then send in yours to do as you please. Wipe out the opposing side's army then march on their capital and destroy their place of ritual. Maybe even filling the place of ritual in such a manner that the teleported enemy champion will be fully encased in solid stone and unable to swing a sword to get out.

If you can't rely on your regular army to entrap the enemy champion, then you could send your champion to do it. This would be a delicate game of cat and mouse with neither hero wanting to strike with their sword unless they are guaranteed to lose. Both heroes would vie for control of the other so that they can incapacitate without they themselves being teleported home. Once one side gains the upper hand, it's attack, attack, attack until the enemy hero escapes or dies. Obviously doing this all with a trusted ally champion gives you massive advantages.

As for (2), this would be the natural course of action after (1) is attempted. Not being able to immediately and accurately identify the champion on the field of battle would allow for deceit of all sorts. This would then lead to chemical warfare to kill off the opposing side's fakes, which would in turn lead to gas masks, which leads to ........

Answer 7

So, each kingdom has a single nigh-invincible living weapon that has a hard time not killing things. For all intents and purposes, this person is basically a deity on the battlefield, with only their counterpoint to stop them.

However, their powers are known, and the person piloting the divine armaments is human under that awesomeness. So tactics, with a side order of strategy can make a insurmountable obstacle less of one. So without further ado let the Wall of Text begin

The First Decision

The first tactical decision of how to deploy the Champion is who to put in the armour. If I am interpreting the question right:

• The sword will make its strike more lethal if they hit. This means that accuracy is more important than power in the overall view
• The Divine Raiment does not improve your skills outside the sword's ability to increase lethality of hits
• The sword can be resummoned at will
• The armour does not negate the force done to itself, though the force the wearer feels is reduced and the armour won't dent/ding/break no matter the force
• Nothing prevents the Champion from committing suicide or from otherwise being struck with their own sword

Thus, the first decision is to enhance. A kingdom could honour its best swordsperson with the honour on the grounds that the Champion's only purpose is to bring glory by making their enemies die for their kingdom. Based on the question, gender should not matter overmuch when it comes to this outside of the societal roles in the world itself.

An alternate tactic is to have somebody more inspiring to don the armour. This tactic limits the raw combat potential of the Champion in favour of using the general tactic of using them as a shining beacon for their side. A person that can rally troops into action and not die to kill that morale boost. Less combative, but it is more like applying a buff to anyone around them by their presence.

Fighting Against

Regular soldiers fighting against a Champion will know that they have no chance -- they will die if struck and they cannot kill them with many forms of direct attack, if at all. Their only hope to slow down or stop a Champion is indirect actions.

The first key for them is to not allow the Champion to dictate the battlefield. If that means a tactical retreat, then so be it. To fight a Champion means to use the battlefield itself to your best advantage. Cover provides additional objects to hide behind that have to be cut through to moved around -- the Champion is still human.

Traps are the primary tactic here. A swinging log might not hurt the Champion or their armour, but it can throw them around with pure force and buy time for people to regroup. A pit trap can potentially trap the Champion for a while, doubly so if you bury the Champion alive when you do it. The Champion is also vulnerable to light and sound and that could be accounted for when building traps and non-lethal measures.

Binding them might or might not work. While the person inside is still human and may not be able to break the bindings themselves, they do have the ability to summon a Sword of Butt Kicking +6 that could potentially cut any bonds if the Champion can maneuver it in the right way. Granted, you might only have to bind them long enough to drop them into a lake, but it is an option. The lake won't drown them (the water can't get in), but it will either delay the Champion.

Lastly, an entire combat style might revolve around killing Champions by getting them to impale themselves with their own sword as that will be the only weapon that could conceivably kill them swiftly. This is the most dangerous of the options, but nothing suggests that the Champion is faster or stronger -- just harder to kill.

Fighting Alongside

Fighting alongside boils down to two primary tactics for the Champion's allies

First, it will fall to the soldiers around the Champion to find and remove traps, ensure that they can be retrieved from traps they do fall prey to, and otherwise keep the Champion from getting into a situation where they need serious rescuing or replacing.

The other job of the soldiers is to make sure that the Champion has a clear path to wherever they are supposed to be deployed to. If they are piercing a line, then it falls to others to make sure that the Champion remains at the head of their formation so that they can continue to do so. If allies can limit the directions that a Champion needs to worry about, then that frees more of their attention to do what they were called to do.

A notable thing for allies is that nothing says that they cannot wield the Divine Sword as per the question. A tactic might be to give it to an ally for them to use. The Champion is the mobile shield while a highly skilled and lightly armoured mortal swordsman wields the sword. Should they die, the Champion can call the sword back with little to worry about.

Against a Champion

When two Champions are on the battlefield, each has to weigh the value of completing the mission they were given compared to removing their counterpart from the arena.

Removal is easy since all they have to do is touch each other with their Raiment. Since mortal soldiers cannot kill them easily, methodically making their way to their counterpart to trigger the recall is a valid tactic. This banks on the premise that your Champion and their allies are better positioned to complete their mission.

Counter to that is the need to avoid them so as to keep going with their mission. If a Champion's presence is predicted, then the should be traps and other things around to hinder them (see above). It becomes a matter of either ignoring each other and let the soldiers try their best with their Anti-Champion measures, or try to arrange it so they fall into a trap -- the owner of the trap does not matter.

Also as per the question, the recall only happens when the sword strikes the armour of a counterpart. Champions punching and grappling each other technically do not trigger the recall clauses so good old fashioned wrestling is an option.

Champion Combat

Lastly are the tactics of the Champion themselves. Who they are under that armour will give a clue as to how they fight. They know their powers and skills, and different people will utilize those powers in different ways.

A tactic is to take advantage of the general invincibility to wade in with long sweeping attacks, cleaving through anybody in their way almost haphazardly. It is probably the easiest for the enemy to exploit, but this combined with the fact that they can't be identified by the enemy might have them question what kind of Champion they have fielded. Once lulled, a sudden switch to a more refined and/or polished fighting style can put a confident enemy on the back burner for at least a little while.

Other tactics will depend on the person but there is no reason not to make sure that the Champion has additional weapons on them for one thing. Like with fight against a Champion, there might be a combat style that takes advantage of certain properties of the Divine Raiment that a normal person could not handle.

Answer 8

If each side has only 1 champion then attack from 2 locations at once, as their champion can only be in one place at a time. When one of your armies realizes they are fighting a champion they can retreat.

Or you could also make your army fast and nimble (light armor, if the champion has magic sword then why waste effort on heavy armor that can still be beaten). The engage the champion in hit and run strikes, the idea is not to defeat them by force but to a) get them tired by having to constantly run after your soldiers b) pull them away from the rest of your army as well as thier army (or any static defenses their army might have set up).

Answer 9

1. Interfere with the ritual.
   • No churches/cathedrals around, no functional champion. Pick your fights far enough from those.
   • Disable the priests
   • Steal, break or defile the implements used in rituals
2. Sensory attack - because "light and sound transfers normally". Vision impairment - e.g. blind the champion with sun reflecting mirrors or just equip your commandos with disposable cameras with flashes. Or prevent her sleep by broadcasting Justin Bieber at 11 on the loudness scale.
3. Mobility - champions won't climb obstacles faster than a human, neither be able to make her way faster through marshes. Can still be entrapped for some length of times.
4. the champion is just one concentrated source of power, stay diffuse and use range attack - against the supporting force - to bring the champion to exhaustion faster (yeah, sure, she'll recover. Tomorrow, tho')
5. 'bout that supporting force, there's a very limited amount of it a champion can defend at any one time.
6. champion's "blessed" food/water reserves - poison, steal or make them in any way unavailable for when the champion needs them.

(7. make a rope from your champion's mail armor and bind/hang the other champion. He won't be able to cut it, even if he can't die).

Answer 10

Everyone seems to want to remove the sanctified locations necessary for the donning ritual, but why? Simply put, having one champion is a disadvantage, as the enemy will have the advantage of numbers and the perfect counter to your invincible champion, so why not steal the other nation's champions? Remember, they are still human, and supposedly "everyone has a price," so give them the right offer and they'll defect. This can be done by A) convincing priests that you have a divine right to rule and that they must help you conquer the world 'as the gods will it!' B) Recruit someone the champion won't immediately attack, preferably someone they care about, and have them use their influence to recruit the champion, and C) mind control. Sound and light gets to champion, which allows hypnosis and playing brainwashing messages to them while they sleep.

Succeed, and you have a small army of invincible soldiers, which virtually no one will fight against. Congratulations, you've conquered the world! Fail, and, well...."why is it the good guys always win?! Dang you meddling paladins!"