A Midsummer Night's Dream is a play about love. All of its action—from the escapades of Lysander, Demetrius, Hermia, and Helena in the forest, to the argument between Oberon and Titania, to the play about two lovelorn youths that Bottom and his friends perform at Duke Theseus's marriage to Hippolyta—are motivated by love. But A Midsummer Night's Dream is not a romance, in which the audience gets caught up in a passionate love affair between two characters. It's a comedy, and because it's clear from the outset that it's a comedy and that all will turn out happily, rather than try to overcome the audience with the exquisite and overwhelming passion of love, A Midsummer Night's Dream invites the audience to laugh at the way the passion of love can make people blind, foolish, inconstant, and desperate. At various times, the power and passion of love threatens to destroy friendships, turn men against men and women against women, and through the argument between Oberon and Titania throws nature itself into turmoil.
In A Midsummer Night's Dream, love is a force that characters cannot control, a point amplified by workings of the love potion, which literally makes people slaves to love. And yet, A Midsummer Night's Dream ends happily, with three marriages blessed by the reconciled fairy King and Queen. So even as A Midsummer Night's Dream makes fun of love's effects on both men and women and points out that when it comes to love there's nothing really new to say, its happy ending reaffirms loves importance, beauty, and timeless relevance.
A Midsummer Night's Dream is a play containing other plays. The most obvious example is the laborers' performance of Pyramus and Thisbe, and their inept production serves three important functions in the larger structure of the larger play. First, the laborer's mistakes and misunderstandings introduce a strand of farce to the comedy of the larger play. Second, it allows Shakespeare to comment on the nature of art and theater, primarily through the laborer's own confused belief that the audience won't be able to distinguish between fiction and reality. Third, the laborers' play parodies much of the rest of A Midsummer Night's Dream: Pyramus and Thisbe are lovers who, facing opposition from their parents, elope, just as Hermia and Lysander do. So even as the lovers and Theseus make fun of the laborers' ridiculous performance, the audience, which is watching the lovers watch the laborers' play, is aware that the lovers had been just as absurd.
A Midsummer Night's Dream also contains a second, subtler, play within a play. In this play within a play, Oberon is playwright, and he seeks to "write" a comedy in which Helena gets her love, Lysander and Hermia stay together, Titania learns a lesson in wifely obedience, and all conflicts are resolved through marriage and reconciliation. And just as the laborers' play turns a tragic drama into a comic farce, so does Oberon's when Puck accidentally puts the love-potion on the eyes of the wrong Athenian man. And yet Oberon's play also serves a counter purpose to the laborers' play. While the laborers' awful performance seems to suggest the limit of the theater, Oberon's play, which rewrote the lives of the same mortals who mock the laborers' play, suggests that theater really does have a magic that defies reality.
After their surreal night of magic and mayhem in the forest, both the lovers and Bottom describe what happened to them as a "dream." They use the word "dream" to describe their experiences, because they wouldn't otherwise be able to understand the bizarre and irrational things that they remember happening to them in the forest. By calling their experiences dreams, Bottom and the lovers allow those experiences to exist as they are, without need for explanation or understanding. As Bottom says: "I have had a dream, past the wit of man to say what / dream it was. Man is but an ass if he go about t'expound this dream"(IV.i.200-201). In a famous speech near the end of the play, Duke Theseus brushes off the lovers' tale of their night in the forest, and goes so far as to condemn the imagination of all lovers, madmen, and poets as full of illusion and untruths. But Theseus's argument overlooks that it is reason, as set down in the law of Athens, that caused all the problems to begin with. And it was the "dream" within the forest that solved those problems. Through this contrast, the play seems to be suggesting that dreams and imagination are as useful as reason, and can sometimes create truths that transcend reason's limits.
The relationship between men and women echoes across both the mortal and fairy worlds of A Midsummer Night's Dream. More specifically, both the fairy and mortal plots in the play deal with an attempt by male authority figures to control women. Though Theseus and Hippolyta appear to share a healthy loving relationship, it is a love built upon a man asserting power over a woman: Theseus won Hippolyta's love by defeating her in battle. Oberon creates the love juice in an attempt to control his disobedient wife. Egeus seeks to control his daughter's marriage. And while the play ends happily, with everyone either married or reconciled, the love on display is of a very particular kind: it is a love in which women accept a role subservient to their husbands. To a modern audience this likely seems rather offensive, but an Elizabethan audience would have generally accepted that men are the head of the household just as the king is the head of society.
Also, A Midsummer Night's Dream suggests that love can also take a terrible toll on same-sex friendships. Even before the lovers get into the forest, Helena betrays her friend Hermia for love. And once they do get into the forest, all the intense feelings nearly cause the men to duel and brings the women almost to blows as well.
In A Midsummer Night's Dream, Shakespeare has created a fantastical world of fairies and magic. And this world is not just a pretty backdrop for the events of the play. The fairies and their magic are the engine of the plot: Oberon's love juice sets the plot in motion, Puck's mistakes applying the juice and his mischievous transformation of Bottom's head into an ass's head complicates it, and Puck's tricks and illusions to keep the mortals while he fixes his love juice errors bring everything to a resolution. And in the face of this magic, mortal dilemmas such as the laws of Athens fall away.