The audience first sees Puck as he and another fairy servant discuss the hilarious pranks Puck plays on unsuspecting humans. He frightens maidens, makes beer flat, misleads wanderers so they become lost, and makes people fall as they go to sit on their stools. His antics amuse himself as well as his master, Oberon, and they have garnered him a reputation. Puck is irresponsible but not malicious; if he poses a danger, it is out of a disregard for mortals, not a dislike of them. When he mistakenly puts the magic flower nectar on Lysander's eyes, it causes strife among the lovers and annoys Oberon, but Puck finds the situation amusing. There is no real protagonist in A Midsummer Night's Dream, but Puck drives much of the plot and is the only character to move between all three worlds—fairy realm, Athens nobility, and Athens commoners. He ties these worlds together with his enchantments, and his words close the play.
The weaver Nick Bottom, one of the tradesmen recruited by Quince to perform in the play about Pyramus and Thisbe, eagerly volunteers to play not just the lead role but the smaller roles as well. His belief in himself as an intelligent man, a great actor, and a poetic writer is at once annoying and endearing. Bottom's transformation by Puck serves a plot need—Titania must fall in love with something hilarious for Oberon's revenge to be satisfying—but it also reflects on his personality: he is an ass. The other mechanicals share Bottom's belief that he is vital to their play, so when he is suddenly transformed into a donkey-headed man, they are frantic. Their joy at his return and the subsequent "success" of the play provide a lighthearted ending to the main plot.
Helena begins the play as a pathetically-in-love young woman who speaks at length of her jealousy of Hermia and love for Demetrius. Although her hope is unreasonable, she tells Demetrius of Lysander and Hermia's elopement plan, hoping Demetrius will like her just a little. She follows after him into the woods, vowing to be his "spaniel." Helena's apparent low self-esteem persists even after she is the object of both men's desire. After Demetrius and Lysander are enchanted and follow after her with longing in their eyes, she gains power over them; however, rather than feeling glory, she believes they are mocking her. When Lysander is reunited with Hermia, Helena seems to accept Demetrius's adoration with contentment.
Hermia's love for Lysander and her commitment to marrying him despite her father's command set up the conflict of the play. Their plan to elope takes them into the woods, with Helena and Demetrius following. Therefore, Hermia plays an important role in driving the plot. She also plays an important role in the play's humor. Beginning as the beloved of both Lysander and Demetrius, Hermia is both perplexed and angry when Lysander and Demetrius fall in love with Helena. Her fight with Helena in the woods marks the pinnacle of chaos and comedy in the play as the two women trade insults and try to physically hurt each other.
Titania's feud with Oberon wreaks havoc on natural systems, such as the weather, and inspires Oberon to obtain the magic flower that will cause her to love whatever living creature she sees. That later turns out to be donkey-headed Bottom.
Oberon's fixation on forcing Titania to relinquish the changeling boy is the substance of their marital quarrel. His vague instruction to Puck—to place the magic flower nectar on the man in "Athenian garments"—causes Puck to mistakenly enchant the wrong Athenian.