Red Dead Redemption 2: 9 Ways You're Playing It Wrong
5. Maintain Honour In Dishonourable Situations
Does a person's acts define them? Does someone deserve a second chance after a life of crime? Is there a way for Arthur to "do good" when he's otherwise defined as an outlaw?
These questions aren't meant to have defined answers, but you'll get more out of the story missions - and narrative overall - by playing Arthur as honourably as possible, come the game's final scenes.
To do so, use the lasso to tie people up rather than killing them. You're free to shoot O'Driscolls and Murfree Broods all day long, and you can absolutely return a punch if you're struck first, but sometimes you might want to steal a stagecoach or horse for one of the Fences, and though you'll take a minor Honour hit when mounting your quarry of choice, it avoids the bigger dip of killing someone.
Also note you can win the majority of duels - including against the Legendary Gunslingers - by shooting the pistol out of your opponent's hand, resulting in a positive Honour boost.
Unless the game is making a point of it, there's almost always a way to play honourably. You just need to get creative.