# Are “Midas” swords useless for warfare?

Are swords, spears, and arrows that turn slain enemies into pure gold useful, in medieval combat, or are they useless aside from free money?

• flesh wounds don't turn people to gold; they need to be killed
• it also works on corpses
• How much of an injury do they need? They need to inflict enough injury to actually kill outright normally, or just a flesh wound? Can they be used on people who are already dead? – Cadence Jul 29 '18 at 5:06
• it would certainly change melee, you would be effectively building a wall every few minutes. – John Jul 29 '18 at 5:08
• "Free money": more gold mean inflation, lot of new gold mean hyperinflation, and collapse of gold value. – Kepotx Jul 29 '18 at 5:13
• how common are these swords if everyone has one then both the gold and psychological gain would lose most of its value (and is magic common as well). but if its just the one sword then it could be a very worthwhile asset in war time (as stated bye everyone else). in peace time it could be used as a interesting way to execute someone (or a ritual killing for your gods) until we know more about your world it will be hard to say – Creed Arcon Jul 29 '18 at 6:19
• How does conservation of mass work? Gold is about 19 g/cc people are around water = 1g/cc. A 150 pound warrior turns into a 3000 pound statue? Or turns into a 150 miniature warrior statue? Does it only turn the person into gold, or does it turn clothing etc? What stops the conversion from affecting the whole planet by proximity. – Sherwood Botsford Jul 29 '18 at 16:59

Honestly, the best use of this would be to turn corpses (their and yours), waste, and the like into nice safe gold. Campaigning armies in medieval times suffered greatly from disease, and poor hygiene was a major part of that. The fewer dead bodies and other disease-spreading elements you have about, the better off you'll be.

• I wonder what the environmental impact of converting tons of organic, bio-consumable material into gold would be over the course of time and several wars. – kojiro Jul 29 '18 at 12:36
• @kojiro I'd be more worried about the economic impact of having a massive glut of gold entering the market after every battle. – jwenting Jul 30 '18 at 11:14
• @kojiro several hundred cubic meters of gold dumped into the local economy suddenly after a battle isn't going to have an impact on that economy? At the very least it's going to cause rampant inflation, and quite possibly extreme local shortages as the guy wielding the sword has sheer unlimited funds to buy everything he wants, from food to land to women. – jwenting Jul 30 '18 at 12:04
• It's not like anyone would use gold as money in a world where it's this common. Maybe they'd cover houses in it to get a pretty and durable surface. – JollyJoker Jul 31 '18 at 7:50
• @jwenting: I would imagine in a world where gold can be created from nothing that gold wouldn't be the basis of an economy. – Chris Jul 31 '18 at 12:59

Assuming they are rare or entirely new, even a single one of these weapons would turn the tide of any war, but it would never see battle. Just follow these simple steps:

1) stab a few cows

2) hire all the mercenaries

3) capture whatever important places your mercenaries can reach

This will continue to work until the market becomes flooded with gold, so it's important to never show the weapon to anyone who doesn't understand basic economics. But if its use is well regulated, you can go around hiring massive mercenary items for years.

• I think you mean "to anyone who does understand basic economics". Or do you mean they'd have to understand economics to understand why they have to keep the secret you're trusting them with? Letting anyone see it sounds like a bad idea, if there's any chance anyone will believe their stories. – Peter Cordes Jul 29 '18 at 17:17
• @PeterCordes yeah the idea is that people who understand economics will know not to go around making tons of gold. Generally speaking, you should keep the thing hidden anyway, but if you show it to someone, make sure they understand why using it too much is a dumb idea. – Erik Jul 29 '18 at 17:20
• You could conduct a series of raid into your opponents territory and stab a bunch of cows/peasants/randoms, thereby crashing your opponent's economy with a sudden gold influx – Chromane Jul 30 '18 at 3:13
• So your idea is to literally make a cash cow? – GilZ Jul 30 '18 at 9:02
• Hell of a stealth pun! – Ruadhan Jul 30 '18 at 13:07

Assuming these Midas weapons convert a person into a statue of that person made of solid gold, we are looking at a pretty effective weapon in certain specific circumstances. A person, on average, has a volume of 95 liters. 95 liters of gold weighs just over 1800kg. A typical car weighs about 1500kg for comparison. So these weapons will be extremely effective in situations where the sudden addition of ~1750kg of weight would be catastrophic.

Imagine you're laying siege to a castle. You fire some Midas-tipped arrows at the men in the hoardings. Most of the arrows do absolutely nothing, sticking in the wood or bouncing off the stone. But one of them finds its way in one of the arrow loops and hits a defender in the face. He's killed instantly, and suddenly weighs 1800kg. These hoardings are temporary structures built on the walls to provide a wider field of fire. Because they're temporary, they're not that well-built. They certainly aren't made to handle a sudden, localized addition of 1800kg. The floor below him immediately buckles. As he falls, his arms smash the supports out from below him and a ~5-10 meter section of the hoarding collapses.

Here's another scenario. You're defending in a siege this time. The enemy tries to use ladders to scale your walls. You equip some of your men with Midas weapons. They kill the man on the top of the ladder. One of two things happens. The ladder might just snap immediately. Or the man may fall backwards, knocking anyone behind him off the ladder, smashing any rung he hits on the way down, and killing anyone he lands on. Now your enemy brings a ram up to the gate. They easily break it down. Your men take their positions in the gatehouse, again equipped with Midas weapons. The first few foes they kill will quickly block the gatehouse; there is no way they move 1800kg statues out of the way, certainly not while your men are there fighting them as well.

• Add to this - launching a corpse from a siege weapon, and trigger the change at the top of the arc. The projectile went up weighing ~100kg and came down weighing nearly 2000kg; that's an effective kinetic energy multiplier of 20. Do that with a dead horse, and you're landing 10-ton projectiles on the enemy. – FacticiusVir Jul 30 '18 at 13:45
• Also consider naval combat. Suddenly having a dozen extra tonnes of ballast on the deck can NOT be good. – ThunderGuppy Jul 30 '18 at 21:02
• This is precisely a good use of that weapon, which so much logic put in it. It actually makes sense, those guys with the battering ram will be your blockade. Then after that war, Hire blacksmiths to remove the gold from your buildings. – Mr.J Jul 31 '18 at 4:11
• @Mr.J In this case you'd be hiring goldsmiths, not blacksmiths – jbch Jul 31 '18 at 20:24
• In addition to naval combat and artillery, a barrage of Midas arrows will be very effective at stopping the charge of cavalry or footmen - every slain charger becomes an instant obstacle. – G0BLiN Aug 1 '18 at 15:44

Can i make a good use of this magic for medieval war tactics

Not really. People are easy to wound, but surprisingly hard to instantly kill.

or its useless aside of free money?

All that gold is heavy (making it really hard to transport afterwards), and flooding the economy with so much new gold will cause rampant inflation.

• See generally the fall of the Spanish empire. Unregulated influxes of precious metals destroying an entire economy isn't merely theoretical. – Michael W. Jul 30 '18 at 17:42
• @MichaelW. that's who I was thinking of. :) – RonJohn Jul 30 '18 at 17:52
• Making your thoughts explicit usually adds much to an answer. – jpmc26 Jul 31 '18 at 22:49

The "Midas" sword is an immensely powerful upgrade to siege engines. For example, a counterweight trebuchet can be used to launch a corpse at a fortification. At the exact moment when the corpse leaves the sling, some mechanism brings the "Midas" sword into contact with the corpse. The 85kg corpse becomes a 1640kg gold projectile (~85kg is the mass of a typical trebuchet projectile). Yes, free kinetic energy! For comparision: typical modern day conventional artillery delivers around 1000kg of ordnance per minute.

The use of a siege engine with a firmly attached "Midas" sword and an effective combat range of possibly 250m ensures that any "Midas" sword/knife/arrow things will be kept away from the enemy. A "Midas" arrow might, of course, be a single-use device, but if it only injures an enemy, the enemy (or one of his fellows) can grab it and use it against you. That would be about as funny as throwing a hand grenade at an enemy with the safetly still on.

Obviously, every alchemist in the kingdom will be researching how to upgrade "Midas" swords to a version which turns corpses into tungsten.

Or uranium. I presume one alchemist was successful with plutonium, but he didn't survive his discovery.

Even without the option to yield "weapon-grade materials", "Midas" devices producing gold isotopes, like $^{201}$Au, might be useful for the more "strategic" purposes. $^{201}$Au has a half-life of around 26 minutes and will turn into $^{201}$Hg via $\beta⁻$ decay.

• Or the corpse keeps his kinetic energy and falls on your own troops in front of the trebuchet. – FooTheBar Jul 30 '18 at 10:13
• Except that acceleration would kill the "projectile" before he leaves the sling. – Madlozoz Jul 30 '18 at 12:43
• @FooBar There would still be free energy involved, namely potential energy. My reasoning is that when you can get one kind of free energy, you can also get another kind. And taking into account the theories of relativity, kinetic energy and potential energy are not really different things. On the other hand, I am not aware that Einstein did mention anything on how his theories fit together with spontaneous transmutation (or quantum physics). – Klaws Aug 1 '18 at 13:37
• Free kinetic energy? What about conservation of momentum? The projectile would just slow by the same factor as the mass increase... For the free potential energy you'd have to work out a way of killing the projectile at (or close to) the top of its arc... – colmde Aug 1 '18 at 15:55

Tactically speaking, I don't know that that's particularly helpful. Yes, you would certainly be able to make a wall of golden corpses, and yes, you would definitely be rich after a good slaughter, but it's not a terribly useful magic for weapons. I would think it would get in the way, having a battlefield full of oddly posed golden soldiers, probably with sharp objects sticking out and ready to stab passersby (like you). One thing you might be able to do, if you're dastardly and need a plot twist, is to set up your magic-sword character on the wall of a castle under siege. If the enemy is at the gates and all the defenses are exhausted, your reluctant hero could potentially make the dark hero choice to murder his companion(s) with the sword, chuck the golden corpses into the vats they'd used to boil the oil they presumably already poured down on the invaders, and drench the enemy leader in molten gold, perhaps saving the castle and giving the hero lots to be moody broody hero-y about. That's a very specific scenario though.

In the realm of psychological tactics, a weapon like that could be huge. Depending on how common magic is in your universe, a weapon that turns the slain into gold could be a massive psychological factor in war. Just imagine coming up to a village, all the buildings torched, everything in ruins, and finding your fallen comrades, forever frozen in their deaths, in gold. You could set up the dead as statues, warning their people of the consequences of challenging you and yours. Then, they have the added conundrum of what to do with their fallen comrades. Do they bury them? Melt them down for coin? How does one cremate a golden statue? And then there's the religious question as well: what happens to one's soul if one is turned to gold? If your enemies are religious, knowing they might be turned to gold could give them pause in considering war.

• That dude defending from a siege would get great mileage by killing dudes on ladders. Turning a body to gold would be heavy to block when it fell and awkward to navigate around if it clung. – The Nate Jul 29 '18 at 6:25
• Why butcher your companions? It's a siege. People are going to die anyway. You'll have plenty of gold to pour over your enemy. Or, you know... you could bribe them to go away. – Erik Jul 29 '18 at 8:37
• @Erik: I think the question requires that they actually be killed with the weapon rather than poking carcasses – nzaman Jul 29 '18 at 11:40
• @nzaman according to the comments it works on corpses. – Erik Jul 29 '18 at 16:26
• No, you would not be rich after a good slaughter. Gold's value depends on its scarcity. You've just created a lot of gold, it's no longer scarce, and hence commands little value. – jamesqf Jul 29 '18 at 17:57

## The exact opposite of free money

Gold itself would not be used to back a currency in this world because anyone with a Midas weapon could make more of it too easily. As such silver would likely be the currency of choice, and thus turning enemies into gold would not yield free money. Also, as I will explain turning stuff into gold will actually cause the war to cost more money.

## Trapped in golden armor

As mentioned by others as people are struck by these Midas weapons they will turn to gold. Even if it only caused their outer garments that were struck to turn gold this could still pose problems. Gold is a soft metal when compared to other metals, but is heavier than iron. Here are some examples of the kinds of problems: - Plate mail and swords: Become heavier and softer - Leather and cloth armor: Become rigid heavy death traps - Shields: Become too heavy to hold up - Chainmail: Becomes heavy armor with every ring being a weak point which could pull apart

With Chain mail if each ring was considered a separate item for purposes of turning into gold, it would likely become the favored armor of choice against Midas weapons. Only the area struck by the weapon would turn and result in only a minor compromise of the armor's strength with each blow from the enemy.

## Scorched earth tactics

If enemies in their entirety become gold upon strike this would result in some amount of scorched earth. Any enemy that is converted to gold would mean that their weapons, armor, clothing, food, and other utility items they are carrying would become gold too and thus no longer would be useful for an on going war. This would drive up the cost of war, and with gold not being an acceptable currency would increase the financial burden of the war.

## Unused Midas arrows

After World War II bomb removal squads had to go around and find unexploded munitions and carefully remove them. In this field if a bunch of Midas arrows were fired on an enemy unit some of the arrows would have missed their mark and ended up stuck in the ground. All these unused arrows would need to be recovered, lest they accidentally kill one of your own people when someone accidentally steps on the arrow head or a kid pulls one out and pokes someone with it. This would cost time and resources.

## Gold corpses on the field cost money to remove

After a battle is over the field will be covered with golden corpses. Burying and burning dead corpses is typically straight forward, but if they are turned to gold then it is going to take more effort to clean it up, which again will cost time and resources. Luckily though a lot of this could be mitigated since craftsman likely would be willing to take the gold as decorative material, but it will take some time for them to haul all that gold out of there. It would mean your cities are decorated in lots of gold or the roads would be made out of gold.

## Other tactic changes

With people turning into golden statues on the field would cause changes to combat tactics. First mounted combat would quickly die down. Golden statues would create a dense area of hazards which would make it very challenging for a horse to move quickly through.

Second as enemies turn to gold it will cause the battlefield to turn into a maze of golden obstacles. As such the field of combat would quickly expand out as people tried to get out of the more densely packed golden zones and thus a larger area would become the battlefield.

Third, enemies will fire Midas arrows back. If I was laying siege to a castle where the archers were firing Midas arrows at me, I would make sure my forces had good cover and were spread out as much as possible. The goal being that as cover was turned to gold Midas arrows that hit it would not activate and with my forces spread out more arrows would hit the ground. I would then have my forces collect those arrows, at which point I would be inclined to return them to sender.

• OP said that the effect was on dead bodies, not on clothing of live ones. – WGroleau Jul 29 '18 at 15:01
• OP said it had to be a deathblow, so stepping on arrows would do nothing but hurt. – Aethenosity Jul 29 '18 at 16:53
• @WGroleau: how does the weapon "know" the difference between stabbing a piece of leather (dead cow) when it's being worn or sitting on the ground? Upvoted for pointing out this potential corner case that the question didn't address. But the question did specify living things or corpses, so I don't think metal objects like links in a chainmail shirt would convert. – Peter Cordes Jul 29 '18 at 17:22
• Don't ask me, ask the OP who explicitly stated only dead bodies. – WGroleau Jul 29 '18 at 22:20
• It's magic, so OP's rules – pojo-guy Jul 30 '18 at 4:17

Flooding the market with vast amount of gold is going to be make gold lose much of its value. First reason not to be fond of using them.

Second reason: on a close combat range, it can happen that the killed enemy corpse falls on the fighter at the end of the combat. Removing a 70 kg corpse is difficult. Removing a ton golden corpse with no help is going to be impossible. Also, you don't want to scatter the battlefield with shiny heavy boulders hampering your troops' movements.

Therefore the tactical usage you can do of this weapon is simply as cash machine: when you need money, just use a knife or a small blade to kill a small animal and cash a small amount of gold. If it works on wood you can also stab a log.

• Actually, density of gold is 19.2 (call it 20). Density of human flesh is roughly 1. A 70kg corpse wouldn't become "a few hundred kg", it would be 1400kg - so well over a ton! – Martin Bonner supports Monica Jul 30 '18 at 8:20

A major problem would be cluttering the battlefield.

Unless the Midas users are purely on the defensive, gold bodies would cause a lot of trouble for movement. Dead bodies are bad enough, but they're not necessarily slippery and can be kicked or moved without breaking a foot. With gold, kicking a dead arm would be like kicking a boulder, trying to shove aside a body to save a companion would be nearly impossible. Stabbing someone in the chest as they charge you will have you under several hundred pounds of gold.

Even if you are fighting defensively, once you get enough gold bodies piled up any attempt at attacking fleeing enemies is gone. It would be impossible to climb over them. It would also make attacking them extremely difficult, but it reduces the choices for the defenders.

So these would not be very useful.

• In the niche position of defending the top of the wall, it would be great. Stab one guy, he falls on a bunch below him. Arrows would also be useful, since then you're dropping the heavy dead bodies in your opponent's line as they advance, rather than in the middle of a melee. – Cadence Jul 29 '18 at 5:21
• Yep. Like I said total defense is about the only place it would be useful. – Dan Clarke Jul 29 '18 at 5:41

Does it only work on humans?

As in, if you jumped on top of a war elephant and plunged the sword into its brain killing it instantly, would the entire elephant turn to solid gold?

How fresh does the corpse have to be? Could I go to the local cemetery and turn it into a mining operation?

How does the process work? Is it instantaneous? Do I run the risk of having my sword stuck in a gold statue? What happens if I kill someone with my deathblow but the sword gets stuck in a rib or piece of armour then the corpse turns into gold while I'm trying to pull it out? Does the corpse turn into a solid block of gold or only the structural parts of the body? So if a gold corpse was sawed in half could we see gold organs, bone structure, fine gold powder where blood was? That would certainly make transportation easier as it would be easier to make the corpses into smaller parts. I'm assuming too that the body gains weight to match the denser properties of gold though it might be that a person who weighs 75kg is turned into 75kg of gold, not hundreds of kilos.

What about wounding someone first? If I cut off an enemy's arm without the injury being fatal and then take his head off, does he still turn to gold? Other than his arm on the ground of course.

I do see a big logic flaw in this. If only deathblows work to turn people into gold, but corpses can also be turned, then why fight with such a weapon? Why not just show up after the battle, find a few corpses and there's your gold? You also vastly reduce the risk of dying.

It would be better if only the living could be converted as the sword requires living matter to work. If corpses are fine too, then like I said above, you could raid cemeteries for gold resources which seems too convenient.

There's 16 good answers to this already, but I'd like to throw my ideas into the mix as well.

First, I'd like to dispute the fact that unlimited gold would tank the economy and ruin everything

The most basic guiding principle of any economy is that Things are worth what people believe them to be worth. The concept of price changes due to supply and demand is a relatively recent one. Modern humans know to be on guard about the economic effects of obtaining and trading a huge amount of supposedly scarce resources. Pre-industrial humans much less so.

The idea that gold would instantly become worthless is one borne off traditional economic assumptions that information is free-flowing and instantaneous, and people have perfect information. In a mediaeval context neither of these things are true. So while, yes, gold would become devalued in the long run, there is plenty of time in which to exploit man's greed for gold and reap huge economic benefits.

As the king of a small sovereign state with a single Midas sword, this is what I'd do:

Use it for executions.

Keep its existence hidden as much as possible, and wrap the process of turning criminals into gold into a ritual with a whole lot of religious mysticism.

Use the first 'batches' of person-gold to forge alliances with neighbours and hire mercenaries if the setting allows.

Just like the modern diamond trade, you have essentially a monopoly of large amounts of gold and can artificially restrict the supply while trading initially small but slowly increasing amounts of it.

Eventually, when my position is secure enough, I will start decorating the city with it. Let it be known far and wide of the Golden City, the new hub of trade, wealth and Philosophy. Once a place is established as the must-go location for trade and pilgrimages, that reputation sustains itself.

Some practical military uses for gold

Gold is almost twice the density of lead. While it is considered a soft metal, a club made from gold is still going to hurt like hell. Furthermore, there was good evidence in ancient treatises that lead projectiles thrown from slings were especially deadly, owing to the density and lack of air resistance from a small lead sling-bullet. Gold sling-bullets would presumably be even more lethal. If gold can create a military advantage, I say use it!

I think a 'Midas sword', if used judiciously, sparingly and secretively, could be used to great benefit to the Ruler in the right circumstances.

• Hmm.. if gold is abundant, you could could use gold pipes instead of lead pipes for water (the ancient romans used lead pipes a lot) – Julian Egner Aug 3 '18 at 6:53

## Psychology

Having your fellow soldiers die next to you on the battlefield is already pretty traumatic, but at least it's not too hard to convince yourself they're at peace now, and often to "help them along their way" by burying them or having some other ceremony to dispose of the body (I've seen quite a few examples in fiction where one side asks or both sides agree to be allowed to bury their dead, which is a whole lot less practical here).

Now imagine they were to instead be frozen in place while screaming in pain. Are they dead or are they somehow still alive in there, forced to feel that pain and unable to move as long as the statue stands? If they're still alive, is there a way to reverse the "goldification"? Also, imagine the conflicts if one person thinks their thoughts are frozen and they can be brought back somehow, but another thinks they are in a constant state of unbearable pain and leaving them is just prolonging their suffering.

What might be even worse would be having to go back to the battlefield tomorrow and seeing them exactly how they died and unable to do anything about it.

Not only that, but the battlefield might still be scattered with the dead of the last army who tried to attack you.

Additionally, any given soldier getting hit on the battlefield could run around screaming, crying and begging while they slowly turn to gold.

This could very well destroy the morale of any enemies you might have.

## More evasion

If you turn anything into gold with one touch, that would likely change the battle to focus more on avoiding getting hit.

Soldiers would prefer light or even no armour.

The enemy might focus more on sneaky tactics instead of facing you on an open battlefield.

A few arrows would destroy any tight formation (since it would be kind of difficult to hold a formation around some giant blocks of gold), so the enemy would be more thinly spread (either initially or eventually).

Any sort of constructs (catapult, etc.) would get disabled in one touch, so those would be virtually useless.

Some of those things might only be good for you if you know how to take advantage of it (assuming the enemy is at least somewhat well-prepared).

Although it might create more havoc, confusion and demotivation to mix Midas and regular weapons - focus the Midas weapons on what regular weapons are typically weak against.

## Traps

Would the weapon turn liquid (e.g. water) into gold? If yes:

Take some enemies charging through ankle-high water.

Get a bunch of enemies who are stuck in place.

Although this would be more of a one-off trap.

Or launch a giant ball of something very light over your enemies - shoot an arrow at it while it's in mid-air to turn it into a giant ball of death.

While the use of gold is arguable, I would suggest something more readily convertible to supplies or directly useful such as cattle or iron, it definitely has its uses to turn a body into something solid.

Fast fortifications
Who said the bodies need to be converted at the place they died? You can build castle-like fortifications super-fast and cheap from bodies. If you are evil, friendly bodies will do, either already dead civilian populace from old age/disease or drafted for "building fortifications" (not disclosing the real meaning).
This tactic could be used even on battlefield for quick makeshift charge defense or other defensive maneuvers.

Military engineering
The building potential of readily movable solid material is not limited to fortifications. Enemy burned bridges? Build new one within minutes from their bodies!

Artillery
Assuming same process would work for other living creatures, birds more specifically, you could mount powerful artillery strike against enemy positions even in pre-gunpowder era. Either mass released or trained birds (=smart bombs) killed by Midas arrows or some kind of timed mechanism would turn into deadly projectiles.

Naval combat
Few tons of solid gold on board of enemy ships? Sounds quite powerful. Either delivered from your board and converted later or turning part of their crew.

• Midas's Suicide Pact Catapult Fodder: Give a fanatic warrior a midas dagger to kill themselves, then load them into a trebuchet (the best of ranged weapons) and enjoy the increase in kinetic energy of the human-projectile suddenly increasing in mass by 10x or more and becoming a solid gold Kinetic Impactor. Alternately a timed mechanism attached to a corpse could achieve the same result I guess, but where's the fun in that? – Ruadhan Jul 30 '18 at 13:14
• Swords normally turn people into meat, it's all a matter of what you're willing to eat. – Separatrix Jul 30 '18 at 14:03
• @Separatrix well, for most people eating bodies of the enemy converted to cattle is a bit more morally acceptable than just directly eating corpses. I have to admit not much, but could help a bit. Alternatively, it could be covered up more easily than directly cooking goulash from corpses. Simply put, supplies would be more valuable than gold in both short and long run. – wondra Jul 30 '18 at 14:09

This would be useful for controlling the battlefield. If you kill enough enemies in the right places, you can build barriers.

There are limited tactical implications

Gold is heavy. Turning flesh and bone to gold, by volume, is a local violation of matter conservation. That is useful for making (say) cannonballs - cannons having been invented in the 13th century, they're medieval - and you could also in a pinch use it to create projectiles for catapaults, or similar use in other siege weaponry. It's not very good for building barricades, because it's so soft.

If many Midas weapons exist, gold is cheap

Gold and precious gems were valuable because they were pretty, yes, but also because they were rare. Flowers are also pretty; the one time people kind of sort of used flowers as money was notable for being completely out of control (the tulip bubble).

If too many people have these swords, there will be so much gold that it will still be useful - it looks nice, it won't tarnish - but gold won't be gold in this world. It will be more like costume jewelry.

If few exist, they are too valuable to risk deploying

On the other hand, let's suppose that there are (say) three of these weapons in the entire world, and forging them is difficult. Then the problem is this: Using these for military purposes means putting them in harm's way. Deploying them to any kind of front means a significant risk that they will fall into enemy hands.

This is bad, because gold is still valuable enough that capturing the weapon will be a big boon to your enemies' ability to kick your butt. Therefore you will do better to build your own war chest with the weapon, in a secure place far removed from any battlefield. In fact the exact location of the Midas weapon will probably need to be a secret. It's a big target, those invite raids and thieves.

I cannot see any world changing event (except, of course, that gold would be officially worthless) but it would have interesting tactical side effect, mostly because of gold high density

The density of gold (weight/volume) is almost 20kg/l.

Assuming that the volume of the body is unchanged, an average dead body would now weight 1500 kg.

## Sword fight on foot

If the poor guy is dead before he hits the ground, you'd better move backward before he crushes you.

In a foot battle, this could be used at your advantage as people next and behind a slain enemy are most likely also enemies. A good kick can make the deadly gold statue fall on them.

Also, a wall of dead bodies would make a very good defense

## Mounted charge?

Imagine the enemy cavalry is rushing at you and you have those magic arrows.

If you make an instant kill, the enemy knight is now a large mass of dense metal tumbling amount your lines. Bad, bad idea!!!

Even worse if you kill the horse.

If you are the guy on the horse, shooting those arrows would be fun, but don't use such a spear. If you're rushing at 20km/h in a soft 70kg mass of flesh that instantaneously turn into a 1400 kg mass of metal, it might hurt you a bit.

## Naval battle

LOL

• Of course, this is cheating, but if you make a magic trebuchet that send live people, the trebuchet accelerate a 75kg mass, but it is a 1.5t boulder that arrive on the target. Kamikaze horsemen are also an option – Madlozoz Jul 30 '18 at 12:25

I'm supposing by "useless" you mean "useless to the story".

A lot of the answers here are worried about hyperinflation from production of gold. Actually, used correctly, it could be used to stimulate the local economy, institute development and so increase the wealth of the local lord. But to become that lord... more on that later.

Firstly, does the weapon really not need to strike a killing blow to work? That would be more magically consistent, IMO, the transformation being driven by life energy. But given it doesn't, where does the gold come from? The plane of gold? What entities might be concerned or intrigued by chunks of their reality being transferred to another plane?

As for conservation of mass, there are various ways to do that, but my preference is that there is a drive from the centre of the slain person's soul, that being drawn back to them, to the surface of their body as each part of them outside-in is replaced by gold-- they become a hollow statue. What's inside the statue? Another plotly question to answer.

So, to take over the locale? The main and ongoing difficulty is keeping the secret. If it gets out, others will be after your sword. How one would find people to kill in isolation would depend much upon your character. I think the question is more interesting for a good or (more likely) neutral type. Do they get a job as a healer? A local executioner?

But once you have your starting capital, you can expand outwards, for example start a "philanthropic" nursing home for the terminally ill (do they exist in this world?), which also provides for the grieving families. Side effects caused by magical conditions are not covered by this policy.

Then you can diversify and reduce the risk from discovery. Get rich in other ways and build power. You have insurance for the time being.

Forget using the gold as money, you could make your army wildly powerful with a Midas Sword! Stab as many cows as you can and bring along as many smiths as you can grab, because you are about to make a shiny golden army that is better equipped than any the middle ages has seen before. Metal in general is a precious resource especially in that age no matter how useless it becomes as a currency.

• wooden spears (a weapon widely used by infantry of that age) get sharp pointy golden tips that make them much more effective. hell wood anything coated in gold becomes way more powerful

• need high density projectiles and counter weights to launch at your foes? GOLD!

• wheels coated in gold to make them far more durable and able to go much further without repairs

• golden bricks to make on the go fortifications and defensive positions for your troops

the list goes on about how powerful having an unlimited supply of metal as soon as you need it would be

• Welcome to Worldbuilding, Hatman! If you have a moment, please take the tour and visit the help center to learn more about the site. You may also find Worldbuilding Meta and The Sandbox (both of which require 5 rep to post on) useful. Here is a meta post on the culture and style of Worldbuilding.SE, just to help you understand our scope and methods, and how we do things here. Have fun! – Gryphon Aug 2 '18 at 17:38
• I'd like to point out that 1) gold-tipped spears won't be much better than the wooden ones. Gold is extremely weak for a metal, and very malleable. It basically bends when you breathe on it 2) as you pointed out, gold is heavy. Your fortifications made of golden bricks are not going to be easily portable, and the bricks won't be very large, to make each brick easy to move into place, so it will take a while to build your golden forts. Finally, one of the major problems of any army is logistics. You'll need those cows for food and leather. – Gryphon Aug 2 '18 at 17:41

This weapon has so many drawbacks that I arrogantly declare it 100% useless

• Even if there's just one such sword on the battlefield, after 30 minutes of combat you'd have so many metalic, immovable, bodies on the field that you, the user, would be tripping over them to get to the next enemy. A gold corpse can't simply be pushed over, and if you do, it doesn't lay flat in any sense of the word. it would be like filling the battlefield with giant caltrops.

• Gold isn't valuable because it's gold. It's valuable because it's RARE (well, that and the fact that it doesn't rust or react with anything, but rare is #1). After each battle the gold market will positively overflow with supply, which means the demand drops, which means the price drops, which means gold is utterly worthless. The steel needed to make a good sword would likely become the dominant coin material.

• And we'll ignore the fact that the conversion to gold takes X number of seconds and the killing stroke of the blade over or through your opponent takes Y number of seconds and if Y > X then your blade becomes stuck inside a golden corpse and requires a hammer and chisel to get it out.

• And last, if not least, is the fact that so long as people think gold is valuable, you'll have every arrow, lance, javelin, spear, atl-atl, sling, crossbow, ballista, catapult, shuriken, trebuchet, rock, and pigeon in the country aimed at your chest. So long as they can think of a way to kill you without getting in range of your sword, you're target #1.

• Gold is also really malleable. And don't discount the value of it's non-reactivity. – RonJohn Jul 31 '18 at 23:08
• @RonJohn I mentioned the non-reactivity, but to a society that's still using swords in battle, that fact has very little value. It also doesn't change the reality of the supply-demand curve. What's the issue about it being malleable? How would that affect the usefulness of the sword? – JBH Jul 31 '18 at 23:11
• Malleability and non-reactivity don't affect the usefulness of the sword. I was just commenting that malleability and non-reactivity are darned useful in their own right. – RonJohn Aug 2 '18 at 8:28
• For example, when gold becomes relatively common, you can afford to cover things you don't want to corrode in thick gold foil. – RonJohn Aug 2 '18 at 8:30
• @RonJohn, I must admit that gold would make a good pre-industrial roofing material.... – JBH Aug 2 '18 at 17:19

Yes it is useless. You can imagin a midas sword as todays nuclear weapon. If you are finding nuclear weapons useful for today's war so you do on midas sword on medival era.

1. This kind of weapon can be a reason for consecutive wars from other tribes. So basically you have to hide it somewhere safe and don't show it to anybody.

2. Using it in a war can focus all the army of enemy on getting their hand on the weapon so the midas keeper must be a super warrior to stay alive.

3. The weapon can be a economical power tool so its that much important for a kingdom to not use it as a warfare weapon and putting its ownership on a risk. like todays nuclear weapons.

They would be extremely useful in terms of financing huge armies. But you would be silly to use such assets in actual battle, or even let people know you had them. It would make you a target for every nation or ambitious warlord.

• Or you let everyone know that you have the weapon and if they try to attack you, you will kill some slaves/captives/minions and produce so much gold that it completely looses its value. – FooTheBar Jul 30 '18 at 10:15
• @FooBar if gold loses it's value, you can't hire a huge army with it to protect yourself... simple logic – Kilisi Jul 30 '18 at 13:11
• The other side can also no longer use gold but maybe you have something else to hire a huge army or you have citizens/believers to fight for you and the other army only has mercenaries... simple logic – FooTheBar Jul 31 '18 at 6:27
• @FooBar na... no logic in that, just vague suppositions that the OP never mentioned... logically the other belligerent kills you, and takes the sword and uses it cleverly to finance their world conquest. – Kilisi Aug 1 '18 at 4:18