How to come up with thoughtful positive & negative effect combos for magic items? [closed]

Question

I'm creating a world in the Golden Age of Pirates. I want to add a little bit of magic but no magicians or mana or something like that. I thought of unique magic items that have interesting twists.

A magic item is a seemingly ordinary everyday object but with a positive and a negative effect if you use or carry it. The positive effect is the effect why you want to use the item and the negative effect is the effect that discourages you from using the item.

My goals with this "positive and negative effect" mechanic are:

• force interesting decisions (decisions where, when, how and even if to use a magic item)
• limit the use of magic items (and therefore limit the benefit of the positive effect) through their negative effects rather than through mana or something similar

Also the negative effect can get stronger over time (where time is measured in uses or carrying time depending on the effect) so for example a pair of magic shoes that make you run faster may make you run less faster over time to the point where you can barely walk so you don't want to use them all the time.

To weaken the negative effect the magic item has to rest (not being used/carried) for a time. The longer it rests the weaker the negative effect will get. This mechanic is my explanation for why magic items are often hidden or burried and have weak negative effects when you find them.

For now I think I have one good example for an item and a few interesting negative effects but I lack good positive effects or thoughtful effect combos. I don't know if it would be correct to ask directly for ideas here* so instead I'm asking for a method to come up with good effects/combos.

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Example: Magic Key

• positive effect: Fits in every lock.
• negative effect: If you stick it in a lock it will not get out of the lock for some time (like an hour or a day or a week - depending on how often you used it).
• rationale: Who wouldn't want a key that fits in every lock? You can go to places where you are usually not allowed to go to. But oops - the key gets stuck and so limits the number of locks you can open in a certain amount of time and also increases your chance of getting caught at the forbidden place!

Examples: negative effects

• when using it there is a small chance that something bad happens (e.g. you get sick or wounded) so the more often you use it the more probable it gets that you get the negative effect
• the more you use it the greater the sacrifice needed to activate the magic (e.g. a chest that needs something of value inside it to do something but it gets more greedy with time)
• the more you use the item the more fragile it gets (this is not directly harmful but you have to be more and more careful when handling it)
• the longer you possess this item the more it attracts thieves - no matter how well you hide it, thieves will intuitively look for it in the right place

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* My reasoning here was that asking for concrete ideas would not be as well received because there would not be a single best answer.

Answer 1

Magic items have an agenda.

This would be a rule by which you would determine case by case what the negatives were. And also the positives which might accrue independent of the function of the object. The goal different from object to object but each object has something that it wants.

It might be an action like Frodo's Ring: carry me back to my maker. It might be like Elric's sword: it wants him to get in fights, so it can drink souls. Lesser magic items might want lesser things. Maybe some of these items are powered by ghosts, and the objects goals are the reflection of the goals and wants of that ghost when it was alive. Maybe your magic shoes want to dance. If you do some dancing they will be happy. If you don't do dancing you might find yourself dancing at inopportune times when you are using the shoes. The magic hat might want to be full of money. A magic bowling ball wants to land on toes. Magic pants want to be tight on you and so when wearing them you might find yourself moving towards delicious food.

People might humor their magic item. Some magic items can be humored and a person doing so can be in a good relationship with his tight magic pants. But some just manifest even stronger desires, and stronger benefits and punishments until the person is just the servant of the item.

Answer 2

It sounds like this worldbuilding is for a game, so I am going to go under that assumption. There are a lot of resources for how to balance your game, however, a lot of it can be boiled down to thinking about how your players are going to use each item and how it's presence effects the meta game.

Every item creates around itself an optimal strategy and thus requires a counter strategy. Try thinking about the different builds your player may come up against and how their strategy compares. Is it weaker? If so, what might equalize the balance so that the two opposing parties have a chance of winning.

You can very easily come up with the opposing parties for any item. For example: the key that opens any lock. The opposing party is the person who holds (or last touched) the real key. This person's disadvantage is that they don't know the door is being opened without their consent, but what if somehow they became aware of that the moment the door opened?

The shoes that make you run faster? The opposing party is the unstoppable progression of the march of time. Wearers may be able to act faster, however they will feel like they ran all day just to move across a field, they will become hungrier faster as well. Those foolish enough to wear them constantly will age faster.

This sort of stuff really just comes from thinking about the physics of your world. Every item must have some way that it works, try to think about natural consequences for every action in that physics. I believe I've read this is how magic the gathering cards are balanced. In fact, you may be able to draw inspiration from some of their items.

Answer 3

I believe that it provides a good basis for future consideration. As a start my answer is inspired by The Stormlight Archive and Mistborn book series by Brandon Sanderson. Links at the bottom.

While there are many ways to think about having positive and negative effects to magic, I would suggest avoiding a simple, it does this at the cost of this, mentality. In books that I have read, most magic used was simply mundane, it was usually not an all powerful force that renders its user invulnerable or omnipotent. This magic usually just made the characters who used it have just a little bit of an edge. It tends to be a combination of several magical powers that made the character extremely powerful. While this is not necessary true for all magic, I would encourage you to look at how something as small as enhanced hearing, could make you a better warrior by being able to hear the heartbeat of nearby soldiers. Now a downside of this would be the clang of metal swords causes the user to be dazzed.

I believe it is more HOW you use the magical power than WHAT the magical power actually is.

https://en.wikipedia.org/wiki/Mistborn https://en.wikipedia.org/wiki/The_Stormlight_Archive