Viola’s disguise as Cesario: Viola's disguise as a man named Cesario creates many dramatic instances throughout the play, particularly in the way that it complicates her romantic feelings for Orsino. This deception also leads to confusion and misunderstanding between characters.
Malvolio’s gulling: The prank that Maria, Sir Toby, and Sir Andrew play on Malvolio by creating a false love letter from Olivia is a prime example of how deception can create dramatic instances. The scene is both humorous and cruel, as the characters take pleasure in manipulating Malvolio's emotions and playing a joke on him.
Olivia’s mourning for her brother: Olivia’s decision to disguise herself as a mourner for her dead brother creates a dramatic instance when she first meets Viola/Cesario. Viola is confused by Olivia’s appearance and does not understand why she is being pursued so ardently by someone who is supposedly in mourning.
Feste’s disguises: Feste, the clown, wears several disguises throughout the play, including as Sir Topas and as a priest. These disguises create dramatic instances in the play as characters are fooled by Feste's various personas, leading to confusion and misunderstandings.