My characters are nearing a point in the story where they will sneak into the garrison of the capital city (using disguises) and attempt to give the army some problems by poisoning their water supply and breaking their weapons. I'm using the term "breaking" loosely here, because what I really want them to do is something subtle and clever, something that won't make lots of noise and attract anyone to the room to see what they're doing, but something that is really going to hinder the army when they fight against the other side the next day. I have no idea what they could do, however, short of giving them some kind of fantasy chemical to rub over the blades of swords that will devour steel instantaneously. Does anyone have any ideas or any historical examples to point to?
Maybe alchemy? Something to put on the metal that degrades it? The protagonists sneak into the armory with vials of metal poison, pour it on the weapons and armor to create weak points.
Bows and arrows, and they also use some magic that comes from certain rare, magical stones. Lances will get used sometimes, but mostly swords. And, yes, they have armour, too, depending on what part of the army they're in. I like that idea!
If you want something that's not going to be apparent until they get to the battlefield, I'd say some kind of magic would work best. Any kind of physical alteration would show up when the soldiers inspected their weapons the next morning. I'm just spitballing here, but given that metal comes from rocks, and sand is basically pulverized rock, and glass is basically melted sand, maybe there's some kind of alchemical shenanigans that turns the metal in their weapons to glass. They go to rattle their swords on their shields and have a collective "Oh, poo" moment.
You could weaken the armour on the connected points slightly, this will not be noticed too fast and when they go in battle their armour will not hold and break (immediately?). Making them vulnerable. Other than that, pretty diffcult indeed
beeasy enough to trim the fletching on arrows so they don't fly straight, although setting them on fire so they just don't have any is a more likely option
I ended up going for adding some fantasy poison they were going to use on the wells anyway to the blades, and saying that as well as killing instantly, it also makes metal brittle. They also cut the strings of the bows and chopped the arrows up. (I didn't think about burning them, which is a nice idea!) Lastly, they crushed the magic stones. But when I second-draft, I think I'll have them loosen the screws and thingies on the armour. (And add the poison to the armour, which I didn't think of at the time and just cannot be bothered to slip in now.)
