What makes a protagonist?

Make them have a unique character arc. The key word is dynamic. How to they interact with the other key characters in the story. What do they think of themselves and what do other's think of them? To have an interesting character, there usually has to be a disconnect between their self image and their image in the eyes of society/ other characters.

That's a question with different answers. There's the motives or passions of the flawed character, the kindheartedness or iron will of the nice person, the ferocity or cunning of the evil person. The list goes on. What you need to figure out first is what kind of character you want. You can determine this with that image of them ruling the world, that idea that only the purest of heart can hold the crown, or even a sarcastic remark your character can make. Either way you build off the idea and then ask what makes that kind of protagonist a good protagonist.

It seems strange, but I think flaws are the most important traits of a protagonist because, without flaws, protagonists aren't relatable and become boring. These flaws can be anything; maybe the character is a little too shy, maybe they're too aggressive, maybe they aren't smart with numbers and it brings them distress in their life. Giving the protagonist relatable flaws is what makes them really likable, because everyone in real life has their flaws.

I think the thing is is that giving a main character a lot of flaws is almost never a bad thing because it gives the character lots of things to overcome throughout the course of a story and grow out of. But giving the main character too many pros, too many talents, too many strengths, makes them way too unrelatable and makes the character boring because they don't have a lot of room to grow and change because they're already almost perfect.

To make a protagonist meaningful and likable from your own perspective, I suggest subtly adding some of your own perceived flaws onto your protagonists for them to work through because nobody understands your own flaws better than you and it makes the story feel all-the-more relatable for an audience to read.

That's just my two cents though.

Basically all you have to do is make sure that your audience can emphasize with your protag. You don’t have to limit his character by making sure he’s likeable, but you should give him at least some human traits or quirks that make him more relatable, or else the audience might feel disconnected from him (and therefore the entire story).
Which can be tricky, since you’re kinda trying to find the middle ground between “too perfect and unrelatable” and “too flawed and unrelatable”.

I discovered to keep it in one simple way. Would the character be able to tell the story? Usually, the protagonist is the focus of the story.

The question i ask myself is "in which character should i focus to make the story more interesting/memorable?" and then i focus on that character.

Give them good and bad qualities to make them feel relatable.

I guess I can use my protagonist as an example.

Trisc is a very hyperactive character, but not in the ways you'd expect (Ie, he actually doesn't have a lot of energy to run around, but he's very talkative). He has a very loud voice to compensate for being short, and people like to constantly remind him of it. He doesn't take shit from people, and will very quickly go into defending himself and other people. The way he interacts with other characters varies a lot, and I think this is actually quite important. I know I, myself, tend to act a lot different based on who I hang out with. Some friends I am able to swear around, others I tend to be much more calm and gentle around. This is a very human thing to do.

He is very likable in the fact that he is quirky and says bizarre/really embarrassing things at weird moments. However, he's a bit difficult to like when it comes to his temper and lack of tolerance for very small mundane things. I honestly thought people didn't like him very much, till I had a poll recently, and he came out on top.

So basically, as stated before, if you want an interesting protagonist, make an interesting character in general, and the rest should fall into place.

You've already gotten some good suggestions/advice.

I just want to mention, the protagonist doesn't always have to be an interesting person, if they are surrounded by interesting people or events you can still have an interesting story. Sometimes it's good to have a very "boring" grounded character among a bunch of chaotic events or overly unique people to provide balance. It also allows the reader to see the story from a more neutral perspective.

There's this thing called the "Hero's Journey" which is a really deep look into what creates a good protagonist. I can sum it up succinctly here and then if you want I suggest looking it up yourself. There's a lot of depth to it.

The structure of a protagonist's tale goes like this
Life > Something Happens that Changes their life >They receive mentoring (either by a mentor or of their own experience) > The hero makes a (usually) permanent change about themselves or something else > The hero lives their new life with their lesson learned and the day saved

In terms of Star Wars this is
Luke on Desert Planet > Aunt/Uncle killed by Empire/Leia's message incites him to join Rebel Alliance > Obi Wan trains him > Luke becomes a force user and uses it to destroy the Death Star > Luke now lives as a Jedi who will master the force

But wait, episode 5 is the same as well
Luke lives his (now normal) life as a Rebel > Attacked by the Empire > Luke trained by Yoda > Confronts Vader > Now Luke lives his new life without Han, without a hand, and knowledge of his father.

So as shown in Star Wars, in terms of plot, what makes a protagonist is that they are perpetually learning. Luke didn't stop learning after episode 4, he kept going. This is the most relatable thing for a protagonist because we as humans are always learning as well. I suggest you make sure your protagonist is always growing and adapting. Even in slice of life if you make their attitude towards something, even a minor thing, change over time, you will show something relatable.

The other thing that I think makes a protagonist is that there is something about them that is immediately appealing. Maybe just physical features, or a heart of gold, whatever. In like Cinderella for example, we realize she is gorgeous, good hearted (animals love her), and she has undue hate towards her so we feel sorry for her. All of those things make us immediately sympathize.

I’ve always really really liked my main character to actually be two characters with opposing personalities who work together.

Almost every comic I’ve ever written had two evenly matched leads. Its usually a character who is a little more introverted and their best friend who is the extrovert of the duo. I think having both those archetypes can really help ground the story but also give that relatability that a lot of people look for in two ways: the character dynamic itself and by having the one character that says what the audience is thinking. I think its easy for audiences to project their own relationships with other people in their lives and pick a character who they feel they relate to most.

One of my comics is about a girl who brings her cat to life and it turns out the cat is better at everything she wants to be good at because he lacks self awareness and pretention. So we have a lonely, introverted character paired with a cat who is extremely extroverted because he doesn’t have any regard for social norms for better or worse. And people relate to both characters at different points but whats most relatable and roots the whole story is their dynamic with each other.

What makes a protagonist?

I'd say a lot of the time... it's the antagonist(s).

Strangely, my opinion was formed for years in Independent Wrestling. A locker room from of guys trying to put on a show in front of a gymnasium of people who likely didn't know them. Historically, they developed a narrative shorthand for telling those little stories.

One of the tricks was to send the bad guy/heel/antagonist out to the ring first. Both wrestlers only have the entrance to introduce themselves/"get over". This isn't televised wrestling with it's promo packages and weekly programming... everyone is pretty much tabula rasa.

So the bad guy goes out first...he makes the people hate him. It's easier to get a large group of people to agree to dislike something than to get them all to agree on anything else.

Then out goes the babyface/protagonist, largely initially defined by their relationship to the heel.

Then the rest of the story is told in the ring but built upon the roles as established in the entrances.

A pattern that is often repeated in popular culture/ popular storytelling.

Well, let's be honest the actual definition of a protagonist is just the person leading the story. And it really depends on the genre. Arthur Dent is one of the most engaging protagonists even though he's so nondescript in many ways simply because he is so nondescript in this amazing story. The same in a superhero story would be quite boding. But many superheros in movies especially, although it is starting to change in more recent years, have little personality beyond "justice/save people" and it's their villains who make them worth rooting for. But then you get the villain protagonists like Light or the morally very dark grey like Black Lagoon and a lot of what makes them cool is just that they're cool.

But there is always at least 1 thing that at least 90% of decent protagonists have and that's that they care about something. Usually someone. You hear it a lot. The quickest way to make people care about your protagonist is to show that they care for someone/something too.

Which, in certain genres, is usually in jeopardy because of the antagonist (and keeping in mind the antagonist isn't always a person but can be an event or nature ect.).

Obviously, this isn't some universal rule but it's solid storytelling when told correctly.

No matter what rules we repeat or come up with, they will not apply to every protagonist in every story.

Take ONE for example. We could say that a hero must face conflict from meaningful antagonists so that the outcome is in doubt. This is rather standard advise to avoid meaningless conflicts and the (currently) much hated Mary Sue heroes. ONE appreciates this practice and completely threw it out the window when he created One Punch Man, a series about a superhero who by his concept cannot be beaten. The main conflict of Saitama is internal as he copes with continual disappointments from being unrivaled. We could say that a protag needs a detailed and interesting backstory. Nope, in One Punch Man, Saitama gained his powers from repetitive daily exercise. We could say that a protagonist should have a unique talent which sets him apart from other characters. ONE next created Mob Psycho 100 in which the main character, Mob, has over-the-top levels of psychic powers, but he won't use them against people. He says, "Psychic powers cannot help me do well on tests. They cannot help me speak to girls." Instead of accepting an invitation to join the school's Telepathy Club and be recognised for his talent, he joins the body improvement club and works his short butt off to build some muscle.

The bottom line is that the protagonist is the character who experiences the main story arc. That's all. We mat spend most of our time as an audience with Ishmael or Doctor Watson, but it is Ahab and Holmes who move through the central conflict of the story and thus they are our protagonists. Any additional traits enhance our enjoyment if the protag are gravy.

Usually, a character that is flawed or needs to work hard, is the most liked.
I think a character that is developed slowly through the story by his experiences , is some one that people relate to.
Their is some thing to be said on characters that isn't developing much through the story but he helps the other character in one way or another to improve themselves.

Discernible traits and a good character design. what does the design or the expressions of a character tell you about them? Can you understand or relate to their struggles? The only true answer to this question is that they drive the story in one way or another, and that they have a goal to achieve. That's about it. Other than that I think the other answers in this thread is what makes a good protagonist, not a mere functional one.

Functionally, I figure they need to be a few things.
A.) Our main character; who the story focuses on.
B.) Have flaws that must be overcome. (Are they a jerk? Do they want to fix that?)
C.) Relatable in some format. (Do they like cartoons? Hey, so do I!)
D.) Entertaining; I want to watch them. (This doesn't half to mean funny or action-y. This can tie into relatable at times.)
And
E.) Stuggle. (Semi-related to flaws; they need to struggle throughout the story, and not just be handed a victory by the story. Work for they're reward, and show they're hardships.)
I think that's about it from me, I think a you'd need a better think-tank than me to actually narrow down what makes a particularly good protagonist though, as I'm not that smart on that front.