There are various religions and faith systems that use spells, such as Paganism and Voodoo. Some people wonder if spells cast on others actually work. Whether they do or not may all be a matter of perception.
I remember when I was learning about Wicca in my late teens, my teacher did her best to drive home the widely held (at least among Wiccans) belief that one should never do spellwork on themselves. Any spell cast for personal gain was said to surely fail, and possibly have negative side effects. However, casting spells on or for others was recommended.
Some people feel that casting a spell on another person is a bad idea, unless you have the person’s permission. Some believe that spells cast on an unwitting recipient would fail because that person is not receptive to the incoming magickal energy. Others feel that it would have negative effects, such as a love spell cast on someone else turning into obsession.
Other spell-casters feel that any spell cast on or for someone else will work as planned. Your energy is being sent directly from you to them, and therefore will have the desired effect. I’ve even heard some people say that it’s better if the person doesn’t know that a spell is being cast on them, because if they knew they might negate the spell with their own personal energy. If they don’t know, there’s nothing getting in the way of the spell working.
I have seen instances where spells cast on others appear to work, and instances where they appear to fail. In most cases, spells cast on the unaware seem to have little or no effect, but when they do have an effect, it’s a negative one. When people are aware that a spell has been cast on or for them, they seem to work on a more consistent basis. I’m sure others might have different observations, but this has been mine.
I also have a theory as to why spells cast on or for those who know what’s being done appear to work more often. If you know that someone is doing something to help you, it can change the way you act and react, and you can actually put yourself in better alignment to receive those good things. On the same not, if you know something negative has been cast on you, paranoia and anger may put you in a position to have bad things happen to you.
If you are unaware that someone has cast a spell on or for you, then the effectiveness of the spell is all in the perceptions of the person who cast it. People often believe that their acts have had effect even when they haven’t or we may see failure because we’re not really looking for the results in the varied forms which they may come.
I believe that the effectiveness of any spell, whether cast on oneself or someone else is all a matter of perception. The aware parties may or may not see the spell working. They may or may not actually believe that the spell has the ability to work. I would have to say that there is no actual way to prove whether spells have any effect on others or not.