In A Midsummer Night's Dream, the supernatural serves both to create conflict in the play and to create resolution.
Conflict is created when Oberon decides to punish his wife Titania for not obeying his will and refusing to relinquish the changeling Indian boy to him. Oberon is immensely jealous of her possession of the boy because the boy is particularly beautiful and Oberon had wanted to raise him to be on of his knights, as we see Puck explain in his lines:
She [Titania] never had so sweet a changeling;
And jealous Oberon would have the child
Knight of his train, to trace the forests wild. (II.i.23-25)
Since, Titania refuses to obey her husband, he decides to play a trick on her using a love potion. He is aware that Cupid hit a particular flower with his arrow and that if the juice of the flower is squeezed onto a person's eyelids while he/she is sleeping, when that person awakes, he/she will fall in love with the first seen. Oberon asks Puck to bring him the flower. Oberon's plan is that, while Titania is distracted with amorous feelings over any creature she sees, he can more easily convince her to hand over the boy. Of course his trick also creates a conflict of self within Titania because she falls in love with a man who, due to Puck's own trick, has a donkey's head. Hence, we see that in this instance, the supernatural created conflict within the story line. However, once Oberon has secured the boy, he uses magic, or the supernatural, again to restore Titania and now that their quarrel is over, the supernatural has successfully restored the married couple's unity.
A second instance of conflict we see the supernatural creating within the story line is that Puck, according to Oberon's wishes, uses the magical flower to make an Athenian man fall in love with poor, brokenhearted Helena. However, Puck has no idea that there are actually two Athenian men in the forest that night and innocently mistakes Demetrius for Lysander. He then puts the love potion on Demetrius's eyes as well so that now both Athenian men are pursuing Helena. This mistake creates a great deal of conflict amongst the characters for a few of reasons: 1) Helena does not believe that either man is being sincere and believes that both men plus Hermia are playing a joke on her; 2) Now that Lysander is pursuing Helena instead, poor Hermia has been left without a mate; 3) The mix-up creates a great deal of animosity amongst the characters, especially the two women who now feel betrayed by each other. Hence, we see that the magical flower, or the supernatural, created conflict within the story, conflict that Puck takes great enjoyment in, as we see in his lines, "Shall we their fond pageant see? / Lord, what fools these mortals be!" (III.ii.115-116). However, again, everything is put to rights by the end of the play. Puck uses the magic to make Lysander fall for Hermia again while Demetrius remains in love with Helena.
Hence we see that the supernatural creates both the conflicts and resolutions in the play through the fairies and their use of magic to manipulate individuals.