People interested in spells often wonder if spells backfire. You don't know what a backfire is? Let's say that it happens when the energy of a spell turns against the caster or the spell's beneficiary.
1- YES, SPELLS BACKFIRE
Most websites mentionning spells also refer to backfires. Generally, they are seen as a problem with the spell: the energy you provoke when you cast a spell is supposed to reach a “target” (for example, the person you want as lover), if the spells fails, that power usually vanishes. Yet, in just a few cases, this energy won't disappear but turn against the caster or, more frequently, against the person who want to take an advantage from a spell (for example, the beneficiary of a love spell is the person who should be loved by the “target” of the spell).
2- WHEN DOES SUCH A PROBLEM OCCUR?
From what I have myself experienced and read, there are few explanations to backfires: the target of the spell might be protected by a talisman or a magick spell that will reverse any spell cast upon that person; the feelings of the spell's beneficiary are not pure (for example, if you cast a love spell on someone that you don't trully love, there's a chance that the spell backfires at you)…
When you want to cast a spell that has negative effects (such as revenge spells), you have to be cautious because these spells easily backfire. Practice before you cast those spells or ask the advice of a professional caster.
3- IS IT POSSIBLE TO AVOID BACKFIRES?
Yes. If you need to cast a revenge spell, I suggest you to have a perfect practice of magick. If you are not a confirmed spell caster, you'd better ask someone to do the spell for you. Negative energies easily backfire if you dont have the sufficient knowledge to control them.
Make sure that the results you want from a spell are not only in your mind but also in your soul.
As much as you can, use professional spell casters to do your spiritual works. They can control backfires and avoid them.
Honestly, it takes a long time to be used to magick and its powers. There are persons who worked for it all their life.