There were two different methods in key technique. The first was to use ore to create a key for something, the other is to force it open with magic.

I’d heard about key technique in the upper world of course, but I wasn’t aware of the specifics as to what it was. I’ll test it out for now.

Feeling slightly charmed by my curiosity, I made my way to the entrance door. There was a bolt holding the door closed. Touching it with my hand, I activated key technique.

After consuming a sufficient amount of magic power, the bolt opened.

“…I see.”

“Key technique seems pretty useful, doesn’t it.”

“Yeah, it might be more usable than I initially thought.”

Now doors I wouldn’t have been able to open could be forced open just by using some magic power. But it looks like it still takes quite a bit of magic power since it’s only level one at the moment. In the upper world, locks that could only be opened via magic power were known as magic locks.

It seems the method of creating a key out of ore works for opening up a normal lock. These were called physical locks in the upper world.

Right now I don’t have any particular way to use for that method. In the upper world every single house would have either a physical or a magic lock installed on it, but that was just a measure against burglary and other crimes.

That sort of crime doesn’t really happen here in this village. Supposing someone did try to commit a crime, they really wouldn’t have anywhere to escape outside of the village. As long as they aren’t completely stupid, no one would try something like that.

“Is something the matter, lord Crest?”

“Key technique lets me create both physical and magic formula locks, but I was just thinking that there really isn’t any reason to go out of the way to use it at the moment.”

“Certainly, locks are something you make to protect you from external threats. I don’t think we need to go that far at the moment, but it might be a good idea to make some for the weapon’s shed and food storage.”

“…Ah, you’re right.”

There’s always the off chance of something happening. Like Livia said, it might be a good idea to make some locks for those just in case.

“Um, I’ve seen physical locks before, but I don’t know anything about magic formula locks. What are those exactly?”

“Magic formula locks, commonly called magic locks, are locks that open up in response to the magic power that is registered to them.”

I activated key technique and touched the front door, causing a magic circle to emerge from it. Using key technique further, I registered my own magic power to it. Temporarily removing the bolt from the door, I gave it a push to open it but it wouldn’t budge.

“Looks like the door doesn’t open anymore.”

“It only opens up when magic power from someone registered is poured into this magic circle. Right, I want to register your magic power in it as well so could you put your hand on it?”

“Like this?”

I could tell that Livia had put some power into it. Her cute face, perhaps due to exerting her power, was slightly flushed. I activated key technique and registered Livia’s magic power. After having her remove her hand from it, I looked at Livia.

“Now try putting your hand on the magic circle again.”

“Understood.”

When Livia touched the magic circle again, it emitted a bright light. This removed the pressure from the door that was there when it was locked, so when Livia pushed on the door it opened naturally.

“I see, so that’s how it works.”

“yeah, they use physical and magical locks in important places, but we don’t need to go that far.”

I’m pretty sure it’s usually used on safes and such? They also use two-step locks on prisons that house dangerous criminals. It becomes more troublesome to manage them though, so two-step locks really aren’t used much.

At this level key technique is already more than good enough. I’d need to raise its level beyond 1 to reduce the magic expenditure, but I’m not going to be making magic locks unless I have a surplus of magic power anyway, so it’s not much of an issue.

As I thought, this isn’t really a skill for the lower world. I can freely destroy any of the locks that I’ve made. Since I don’t really need that magic lock from earlier, I’ll destroy it for now. With that, I’ve finished examining key technique.

“I guess I’ll take a look at trap magic next”

“Yes, If I recall correctly it’s magic that can activate stored magic? How is it used?”

“I’ve got some ideas. Let’s go check them out.”

I tried making some trap magic right away. First I had to pick a spot to set the trap. One that’s picked out, I then had to choose the kind of trap it is.

For this one I made it so it would activate when stepped on. After that was the magic that would be loaded into the trap. For that I went with some wind magic that would make a light breeze. Once everything was set, a magic circle appeared for a brief moment before disappearing.

“I can’t see the trap magic.” Remarked Livia.

“…That’s true. But if you put some magic power into your eyes then you can see it.”

“Eh? I can’t see it though….”

“Is that so? Let’s see if I can make it visible somehow…”

Become visible for Livia too, I tried thinking in my mind.

“Ah, I can see it now.”

“That’s good. Now, mind walking on it for me?”

“Eh? Wh, what kind of trap did you set?”

“It’s set to create a light breeze. It shouldn’t be able to hurt you I think.”

“Understood.”

Livia approached the trap looking a little bit nervous. As soon as she got to the spot I selected, a magic circle appeared.

“Kya!?” Even though she knew it was coming, Livia let out a small scream in surprise. “I, it’s fine since I could see it, but it’s a bit startling.”

“That’s true. It looks like there are a lot of ways I can use this, but for now it might be good to set it up at gates that outside enemies might come in and such.”

Even if I call it a gate, it’s still just made of wood. Even the walls are only made of processed wood buried in the ground. It’s better than having nothing though.

“What can you set up as the condition?”

“It seems I can do pretty much anything with it. The magic cost goes up quite a bit with the level of complexity, but it’s still within acceptable limits.”

For example, I could set it to only go off for those who aren’t my allies. In other words, I could make it only go off when someone who I haven’t given a magic name. That would let us launch a preemptive attack on potential enemies. My fantasies were running wild.

“…Lord Crest’s gacha skill is certainly amazing of course, but your greatest talent might be that amount of magic power.”

She might be right about that. It’s evidence that I was born with something good. But, without a good skill, magic power is just pearls before a swine.

Next up is the last one. It’s finally time to take a look at the assassin skill.