Sometimes it’s difficult to make your characters likeable as they are tested and are pushed to further and further lengths. Sometimes they have to make hard decisions, and sometimes the pressure gets to them and they mess up, hurt another character or an innocent bystander. How can you keep them likeable throughout the whole plotline?
– Keep their motivations pure.
It almost always comes back to the heart – if their heart is pure, and that’s established early-on, the audience is more likely to root for them.
– Give them flaws – make them human.
Not every character has to have some huge problem, like an addiction or a traumatic past or a disability – if your entire cast does, it’s no problem, but it’s not necessary. But every character has to have some flaw(s), whether it’s cheating at card games because he can’t stand to lose or being too-closed minded or closing off when she gets too emotional. If your character doesn’t have a flaw, they start to come off as too perfect, too angelic, pretentious.
– Give them permission to mess up.
This ties in with flaws – if your character is inclined to make a bad decision at any point in the plot, don’t steer him away from it because “oh no he’s my protagonist and he must be Good and Whole and Pure and All-Knowing”. Let him walk into that ambush despite the sick feeling in his stomach and get half his army killed; let her rush into a confrontation with a bully and get into a fight with another girl who has a switchblade. Let your characters mess up – it shows that they’re human.
– But if your character messes up, let them own up to it eventually.
The general who killed half his army by ignoring the unease in the back of his mind might cry over their makeshift graves long after the rest of the platoon is asleep; the girl sitting in the infirmary might feel remorse for knocking her opponent’s block off. Or your characters might argue and might be stubborn and might not apologize for weeks. But let them apologize eventually. This goes back to the heart, and what the character knows is right.
– Relationships with other characters are vital.
That’s not to say a loner character can’t be likeable – but the audience’s perception of a loner character is determined by the thoughts/words of other characters. Characters all color each other and define parts of each other, just like people do to each other in real life. If your character is a jerk to other characters and other characters don’t like him (especially if the characters who dislike him are likeable), the audience won’t like him either. The character’s image depends not just on himself, but on his supporting cast.
Hope this helps! – @authors-haven