How do I create scenario where the BBEG defeats the heroes but his heart in changed by the heroes before they are...

Wrong.
This guy has an idea of what he wants to happen at the end of his game before we even has game or even players it sounds like, so this entire thing is basically a masturbatory thought exercise that doesn’t require player participation.
As someone who used to ACT like OP, players will not appreciate it, either because they actively dislike you taking the choice out of their hands by you dictating what happens to them or they won’t even notice or care.

Accept that this is a collaborative storytelling exercise with game rules attached to them, not a medium for you to write a novel in with your players as your captive audience.

Beginning with the OP’s assumptions, yes.

>that doesn’t require player participation.

Except it does. He needs players to play through the game and build up to the moment in his storyline. You cannot leave EVERYTHING up to the players, otherwise GMs might as well not exist.

>Accept that this is a collaborative storytelling exercise with game rules attached to them, not a medium for you to write a novel in with your players as your captive audience.

Said like a truly unimaginative pleb.

OP wasn't making any? They just asked for a scenario and everyone was armchair GMing

You are talking like the players are puppets instead of people.

The solution is to write a book or read a story where this happens and look at the protagonists and the villain.

Unless of course you manipulate the players into thinking they have a choice in the matter when in actuality everything they do would lead to this moment. That way the gm has his cake and the players can eat it too. Just don't ever tell the players you were lying to them all along and that they were always on rails from day 1.

Having a goal in mind does not make it a railroad

>You are talking like the players are puppets instead of people.

Nope, I'm talking like the players are players, not GMs.

>The solution is to write a book or read a story where this happens and look at the protagonists and the villain.

Or to let OP end his game how he wants without shitty replies from moronic plebs.

First you need believable reasons for the bbeg to have a change of heart. The more the better. Then you need to have your bbeg to be susceptible to the reasons for said change of heart. After which you will need your players to do two things. Embody the reason behind this change of heart and bring it to the fore front of the final battle.

The first two parts are easy enough. Give your bbeg a couple of believable reasons for the change to occur like maybe he was doing it because he thought it was the only way to save the world, for example. Then, following that example, use the players as a means to offer an alternate way of saving the world, a better way. However their methods often come into conflict as do their ideals. This will culminate at the final battle when neither side can back down any more. There, at the end of the battle - and here's the tricky part - you need to come off as the bbeg realising that the players were right all along and so he takes on their role and goes on to save the world in their stead. So even as the players have lost, they know that the world they love has been saved and the bbeg has been defeated.

There you go, broad strokes. Not easy to pull off and will need certain types of players to get into the groove but definitely doable

Get the heroes to say "save [BBEG's mother's name]".

Nigga what? Making a story that players follow and a setting to do it in isn't a fucking railroad. If the BBEG set fire to a distant village that was filled with rebellion and the party was no where close to that, would you bitch about railroading there too?

Can't some events in game just represent a story that the players are playing through? You aren't the all powerful gods of any setting where you just swoop in on a whim and save everyone in at the right moment before everything exploded. Part of any good RPG game is story, players having complete and full control over anything that happens in the world isn't a good game. At that point you could end up GMing a game of second life, and the fuck is the point of that?

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Go the fuck back to /v/, dumb wojakposter

The problem is in the 'BBEG defeats the heroes' part. What if the players manage to beat him instead? What if they join him instead of fighting him? What if they turn tail and flee instead of confronting him in the first place? These are things the GM has no control over, and cannot force the players act in a specific way he wishes without railroading them.

Yeah, that's an issue, but one that the GM doesn't necessarily have to include. Maybe if the players are actually doing badly enough in the fight against the BBEG, but otherwise he could be gradually reconsidering his stances and goals during the course of the game and that could all come to a head during the final confrontation.
Of course that doesn't take into consideration the players joining forces with the Bad Dude, but the GM should be prepared for such an occasion. You may not get your 'turn villain good' scenario, but can't always have what you want. Have some fun with the new circumstanes.

This is one of those outcomes that would be incredible play, but inherently can't be planned.
If it didn't happen honestly, it will be without value.
Just play, with strong antagonists driven by real goals. Maybe they don't care too much about civilians, or have blinding religious convictions, but the villains who are EVIL and misanthropic should be rare.
Anyone else can have a change of heart, and I look forward to the day when one of yours does.
Happy gaming, user.

This, if they don't see the rails are they really there?

>This thread
Show me on the doll where the bad GM touched you.

If they turn tail and flee from facing the BBEG, I'm going to blame the players. How are you going to run away from the final fight like that, it's up to the players to finish the story, but giving them a no time leash, it's kind of lame to know that the BBEG is sitting there just waiting for the final fight while the PCs are doing other things because they decided to turn tail and do other things before they go back.