The Red Dead Redemption 2 story mode is a rather linear affair. Most of the story missions don't offer players any choice, and the ones that do only include minor choices which don't alter the course of the story in any major way. There are ways, however, to alter some of the ending sequences of the game, with a final choice in the last mission in Chapter 6 changing the ending in a major way.
As we are going to focus on how to get all of the endings available in the story mode, this guide is going to feature huge spoilers almost immediately, so avoid reading this instant if you have yet to see any of the two endings.
The Honor system in Red Dead Redemption 2 story mode influences a couple of sequences in significant ways.
Depending on your current rating, Arthur will react differently to learning that he has contracted tuberculosis and that he doesn't have long to live. If he's been honorable, he'll take the news in an almost serene way, deciding to do good with the time he has left. If he's been dishonorable, however, he won't take it that well, but will still resolve to do all he can to help some of his fellow gang members get to safety, especially John Marston and his family.
The Honor system also influences some of the story sequences following the big reveal of Arthur's sickness. During specific story events, Arthur will have visions of two different animals, a wolf is he's dishonorable and deer if he's honorable. These changes are small, but they manage to represent Arthur's current state of mind and how he feels about the end of his life that's quickly approaching.
No matter the current honor rating, which ending you get depends entirely on a single choice that can be made during the Red Dead Redemption mission, the final one in Chapter 6.
At the beginning of the mission, the Van der Linde gang is clearly no more, with Dutch, Bill Williamson, Javier Escuella and the traitor Micah on one side, and Arthur and John, who's been left to die by Dutch himself during a prior mission, on the other. A shootout will ensue at the camp, and Arthur and John will try to make their escape from their former companions.
At a certain point during the escape sequence, John will inform Arthur that the money Dutch stashed away to make the gang's escape from America is still where it was left. Later on, Arthur will be presented with a choice: go back to get the money, or help John escape with his life. If you choose the first option, you will get on the path of the "bad" ending.
If you decide to get the money, you will go back in the cave where you will be confronted by Micah. The duel between the two outlaws will end in a draw, and Dutch will step in to stop Arthur from killing the traitor. Arthur will still try to make Dutch see reason, but it will be in vain. Micah will then shoot a dying Arthur in the face while laughing. You will also get a scene with a wolf, which indicates that you have taken a dishonorable path.
While the bad ending isn't particularly bad, it's definitely not in line with the way Arthur approached life after discovering he was sick, as he was resolved in letting, at the very least, John and his family escape, trying to give them a chance to finally start over.
If you choose to help John make his escape, you will be set on the good ending path, and you will end up fighting a lot of Pinkertons on the cliffs. Once you have killed enough, Micah will make his appearance, and the two outlaw will fight against one another with only their fists as their weapons.
Like in the bad ending, Dutch will eventually appear to stop Arthur from killing Micah. At this point, Arthur, now very close to death, will tell his former companions that he tried to change, unlike them. Dutch will stop Micah from finishing Arthur, letting him die in peace.
The good ending is definitely more in line with Arthur's character, and definitely more satisfactory, as it shows how he indeed managed to redeem himself after a life of crime. A short sequence with a deer will also play, indicating that Arthur chose an honorable path when deciding to help John Marston make his escape.
No matter the obtained ending, the game will continue with the Epilogue, where players will experience for themselves how John went from being an outlaw to a farmer. The final mission of the epilogue also brings closure to the story, giving players a final look at Dutch before he disappears until 1911, when the original Red Dead Redemption takes place.
Bonds That Last Forever
While not an ending, there's a special cutscene in the Red Dead Redemption mission which is only played if you have reached the maximum bond level with your horse. It's a very emotional one, so get tissues ready, it's hard not to be moved by it.