There are two closely related characters used to support a main character’s narrative as literary devices: The confidant(e) and the sidekick. If you are creating genre fiction, what the role of these characters are will determine which device you are employing. There are several overlapping functions of the character types, but there are also some clear distinctions.
The confidant (if male) or confidante (if female) is an essential device that prevents a solo main character from occupying too much introspection time. A good story rarely leaves their main characters alone with their inner thoughts, feelings, and intentions. With rare exception, this tends to make for boring reading. I will refer to both masculine (confidant) and feminine (confidante) characters as a confidant here.
Traits of the confidant are:
- They serve as a sounding board, often interacting with their main character regarding the most important decisions. Alfred Pennyworth is a confidant of Bruce Wayne and Batman, as opposed to Robin, who is the sidekick.
- They have insight, with good judgement and sound principles. They create the space that allows the reader to understand the implications of a situation. Samwise Gamgee is Frodo Baggins’ confidant, and alerts Frodo several times about the dangers of using the ring.
- They are complicated. A reader often identifies with the confidant, stepping inside this character and borrowing their ears and eyes when the main character is about to do something. Often, they simply echo the reader’s thoughts (or the thoughts the author intends the reader to consider). So they can not be one-dimensional.
- They prevent the main character from being alone, showing the main character aspects of their own personality. This again is projecting the reader’s perspective into the narrative. Dr Leonard “Bones” McCoy frequently declared the brash nature of Captain Kirk’s decisions as one of Kirk’s confidants.
- They are always close and trusted by the main character. They do not separate from their main character for long, as this can also isolate the reader who tends to become involved in them.
The sidekick character is a literary device typically created for comic relief as the question title states. This doesn’t necessarily mean that they are limited to the comedy genre, it simply means that they provide a relief from what may otherwise be a tense or difficult situation. What the sidekick’s chief roles are can be summed up as:
- Like the confidant, they do provide counsel and assistance to the main character they support. But aid is more in the role of a sidekick than a confidant (which is where the “kick” part of the term comes from).
- The sidekick will help with the main character’s hardest struggles, whether that is a fight scene or a difficult riddle. This can be similar to providing judgement however it is a supporting role, and does not always have to be competent help.
- The reader should always have the feeling that the plot would fail without the sidekick, while the main character is seen as actually accomplishing the resolution. Sidekicks form the second half of a duo or team that reaches resolution together; the sidekick having the lesser share of credit.
- The sidekick needs to remain relevant and important to the plot, while always staying “to the side” of the main character. A sidekick should not be a disposable character. In some versions of the Batman franchise, especially the comic book and the TV series, Robin is actually a bad example of what a sidekick represents, as he really does not contribute to important plot resolutions.
This last part speaks to the question in the title. It forms in effect one of the tests of a true sidekick:
Would Frodo Baggins be dead without Samwise Gamgee?
Yes, Samwise literally prevents Frodo from getting the whole party killed while using the ring improperly. Several times. This means Samwise could be a literary sidekick.
Would Batman be dead without Alfred Pennywise?
Most Batman stories do not put Alfred in that position, he is not a sidekick.
Would Hamlet be dead without Horatio?
Hamlet did die, because he never listened to Horatio. Not one time. So Horatio is not Hamlet’s sidekick. > Would James Bond be dead without M or Q? Not likely at all. Both of these are confidants to Bond rather than sidekicks.
The Savior Sidekick is the norm for this type
A sidekick, when used in the common mode in a genre fiction, will be a comic relief, and will be involved in saving the main character’s life in a prominent way. But having a sidekick does not classify the fiction as a comedy, it only incorporates an element of comic relief into any genre.
The line with a confidant
In most genre literature, characters can wear multiple hats, and some times multiple characters can wear one hat. There is no rule binding any one character to any desired effect in the reader, so there will be times, like Samwise Gamgee, when a character is filling both the sidekick role and the confidant role. In his capacity to save Frodo, he is the sidekick. In a great deal of the dialogue between Frodo and Samwise, he is the confidant. Other times, like Batman, the sidekick and confidant are widely separated between Robin and Alfred, respectively. Then other times still, the sidekick is in multiple persons, such as Ron and Hermione to Harry Potter.
Regardless of who or what wears the sidekick hat, and what other hat they may be wearing, the principle role of the device is comic relief. The example given of Kato to Green Hornet, as well as Chewbacca to Han Solo; Tinkerbell to Peter Pan; Short Round to Indiana Jones; Donkey to Shrek; and Stan Laurel to Oliver Hardy represent the normal mode for this character type, and will be the most commonly seen implementation for their humorous foibles. But notice here, that Han Solo is not the protagonist and still has a sidekick who saves his life many times. R2D2 is likewise the sidekick to deuterogonist C3PO. It is not only the protagonist who can use this device; and complex character with prominent plot interaction should generally have a sidekick helping the reader follow their thought processes. But what about Han Solo? He saves Luke Skywalker’s life one time at the climax of their A New Hope journey. Does this automatically make Han Solo a sidekick? No, Han is mostly Luke’s confidant, but he does manage to be at the right place at the right time, usually against his will and for an ulterior motive. Those features are what make Han also a sidekick.
As indicated, literary fiction is not very concerned with the tropes of genre fiction, although it is free to apply them.
The line for a literary fiction piece would be simply drawn where the spotlight rests. If your support character is in the spotlight and saving the protagonist, then you really can’t apply genre tropes to the work. The author creates a need to keep the reader aligned with the focus of the plot. A supporting character stealing the spotlight can cause the reader to shift their focus, and lose affinity for your protagonist. This character may still serve as protagonist’s confidante (in the OP case), but some other literary device needs to be used to prevent the plot from getting out of focus.
It is generally hard to shift a reader’s loyalties between characters. One technique is to create an abstract character, such as The Force in Star Wars, which acts in the plot and can smooth over shifts in character focus.