If Oberyn had won at Tyrion's trial by combat, how would events have changed in FfC and DwD?

[The Pain Yak]

First of all, Tyrion almost certainly heads to Dorne with Oberyn. King's Landing has obviously judged him guilty regardless of his trial's outcome, and Oberyn has offered him shelter, so it seems the only move that makes any sense. What kind of reception would Doran give him? Oberyn seems to share the Sand Snake's belief that the best plan is to crown Myrcella and fight a hopeless war against the rest of Westeros, but Doran obviously does not, and the act of sheltering Tyrion might be considered too brazen. Would he deny him refuge to avoid antagonizing Tywin? Or would he give him shelter, but secretly? Or something else?

Second, Tywin does not contract a fatal case of crossbow bolt through bowels, with all the ramifications for the Lannister cause that entails. How would he react to Tyrion first kicking his plans to pieces and then getting away with the murder of his grandson, seemingly scott free?

Cersei never gets the chance to run the kingdoms into the ground, but she also probably completely loses her shit when Tyrion is taken off the hook for Joffrey's death. I have to imagine she would start searching for a way to have Tyrion assassinated, far more so than previously. Of course, she is also still trapped in Tywin's intended arranged marriage.

What about Jaime? Or Littlefinger, whose plans for Sansa depend heavily on her being widowed?

And, of course, Tyrion is never in a position to misdirect Young Griff into launching his own invasion of the Seven Kingdoms, meaning he very likely continues to make his way to Dany.

Really, the whole story would change drastically, but to whose advantage?

[The Mountain That Flies]

To your first point, while Doran is a cautious guy by nature, Tyrion is perfect tool, and wouldn't be passed up. He would be housed in "secret", with Tywin and the inner circle at King's Landing probably knowing where he was but Westeros at large not.

There are many theories that Oberyn had already poisoned Tywin, (http://asoiaf.wester...poisoned-tywin/) so Tywin would still die, though it's difficult to say is Cersei would retain power in the same way as she did normally. She would then dedicate an enormous part of the crown's resources into having Tyrion killed, while continueing to act against the Tyrells. Jaime's arc pretty much continues as is, though without Tyrion having taunted him about Cersei sleeping around he may have taken longer to break from her.

Littlefinger is a wild card. He wants to be able to officially marry Sansa to harry the Heir, so he may work alongside Cersei from afar to have Tyrion killed. It's a bit hard to say though.

Aegon would have never reached Dany. Mereen is surrounded, and unless the Golden Company was prepared to kick off a war against Yunkai and all its mercenary companies, they would probably say nuts to that and head to Westeros anyway, though like Jaime with a delay.

Hard to say who this would really benefit in the long run (besides Oberyn's face), but whatever fate awaits Tyrion with regards to Dany would be drastically different.

[The Pain Yak]

For the record, not just asking for thoughts on my own posed questions. I'm guessing the consequences of Tyrion being found innocent and Oberyn surviving would ripple out farther than the ways I've listed.

[Victor227]

I've a personal theory that Oberyn and Doran were playing the game for Myrcella and Trystane at that point during A Storm of Swords. When Oberyn meets Tyrion, he's not just interested in bringing the imp to Sunspear, he wants -Sansa- too. As well, he brings up the notion of bringing Cersei on-side with Myrcella against Tommen. Seems he was interested in lining her up as an alternative to Tyrion.

At this point, Viserys is known to be dead, and Daenerys is missing after the death of her husband. The only card the Dornish have left to to take the crown is Myrcella. So why not? Send Oberyn to King's Landing, and let the situation play out. Oberyn's objective is simple, kill Joffrey and Tywin as soon as the opportunity presents itself, and return to Sunspear with Sansa, Tyrion, and whomever else he can wrangle with a position that can support a claim.

If Oberyn hadn't died, he'd have been bringing the rightful lord of the Westerlands down south with him. The only reason Tyrion was disinherited was because he was found guilty of killing Joffrey, and escaped, murdering Tywin in the process. If he was found perfectly innocent, he still has to rely on Oberyn to protect him in leaving King's Landing, lest the mob take him, so Oberyn can happily take his -large- Dornish escort home with his new 'friend'. Tywin dies when they're miles away (assuming the theory about Oberyn poisoning him is correct, as Widow's Wail is slow-acting), everyone suspects the Red Viper, but he just shrugs his shoulders and they go "That silly Oberyn! He is so murderous!" And Dorne wanted Tywin dead anyway, so who cares?

The original plan would be to have Winterfell, the Casterly Rock, and Sunspear behind Myrcella, and that's a war they -can- win, instead of going it alone. Even if Doran just has Tyrion and his rightful lordship of the Westerlands behind him, he can sow discord using that to his advantage and still have a good, winnable chance, as Cersei does her best to destroy everything, and Tommen's throne will still be embroiled in lingering conflict. Oberyn would come home with Tyron, and with him on their side along with Doran, the three of them would scheme to put Myrcella on the throne and destroy Cersei and leave Tyrion's rule fo the Westerlands uncontested. That's what could happen if Oberyn won in Tyrion's trial.

As is, Arianne came up with a very similar plan. She was just too stupid to realize that Doran had already had that plan, and discarded it as impossible when Oberyn died and they lost their big chance to get Lord Paramount support from outside of Dorne. Of course, Doran then heard that there was still a living Targeryen and sent Quentyn off to Meereen. There's a reason why that plan looked especially careless and fraught with peril. Because it was their third plan, come up with quickly after hearing they still had a shot at the throne.

[Don Roberto]

I doubt things would heat up in Westeros, initially. Crowning Myrcella was a desperate plan by Arianne in response to Doran's imprisoning of the Sand Snakes and news of Quentyn's voyage, but had Oberyn won they'd have never claimed for war in the first place. Instead, the long vengeance against the Mountain would have been carried on, and things would be cooler in Dorne, with Doran waiting for good news from the Narrow Sea.

But then again, Oberyn would be seated in the Small Council, and he deliberately said he was at King's Landing to seek revenge, starting with the Mountain, but not ending there. With him meddling around and Cersei blind with wroth over his assistance to Tyrion, things could take any sort of derailment, from Oberyn being killed to him attacking some important lord and be branded a traitor.

Most likely things would turn out for the worse in King's Landing relationship with Dorne, and the war sentiment might prove too much for Doran to handle. I doubt Doran would make use of Tyrion, leaving him to scheme on his own. He could abandon Westeros altogether, or he could add fuel to the fire and help Arianne crown Myrcella (if for no other reason, to piss off Tywin) - and he'd probably come up with a better plan to do it, one that wouldn't get discovered. The war on the riverlands would probably get diverted to Dorne, especially with Mace on the Council as well. If talks come to facts, Jaime would be sent to the south, which means Riverrun would likely never be taken.

As for Essos, things are much harder to predict. Without Tyrion, the Golden Company could somehow reach Slaver's Bay, or could very well stay camped near the Rhoyne unable to move. I don't think the idea of sailing west would come to any of them. Assuming they do get to Meereen, they'd do so after Dany has left, and either arrive during the war, right before or (most likely) after it. And since we don't know how that plays out, it's too hard to say how Aegon's presence would alter it, if at all.

[The Bastard of Summer]

If the Red Viper would have won for Tyrion, Tywin wouldn't be dead. The whole mess with Ceresi, Marge and the Faith would not have went down either, because Tywin would not have had that do down in his court. Also Tyrion wouldn't have killed Shae and found out she was indeed what her profession proclaimed her to be. So that means Dany would only be getting Victarion and his bad influence and judgement, and not Tyrion who could quite possibly help her along with her campaign to claim Westeros as her kingdom. So this would look really good for Aegon.

[Rheagar Prime]

well it would change alot especially for the targs across the narrow sea. No meeting aegon to set him off to be less biddable and the GC may just head to meereen to more trouble.