Thoughts on Wars of Annihilation.
It is true that this gets problematic for a lot of reasons. I don't think these necessarily counter stagnation. As has been mentioned people form huge alliances to avoid being destroyed. Demanding certain leaders step down as terms of surrender is a much better way to get some turn over out of a war.
The complaint that some realms refuse to surrender is valid, however there are ways around this. For starters, if a realm really has the upper hand they can let the war go cold. Drawn out hostilities can add just as much fun and intrigue as a cataclysmic battle. Also players in the realm being defeated should consider rebelling or protesting if they want to save the realm.
I've also seen the opposite with realms refusing to accept a peace even when they can't reasonably hope to achieve victory. It's annoying but I think it's made possible in part by the lack of intra-realm conflict. How Luria Nova managed to have such high player density yet no internal strife for so long is beyond me.
I think creative new ideas for terms of surrender is a good thing to discuss. Going off my exchange of prisoners idea, one term of surrender could be that certain key members of the defeated realm must swear a binding oath never to return to the lands of their former foes. How do you make this oath binding you ask? Simple, they have to briefly join the realm and then be banned. Once that happens they're fair game for execution. Of course at some point the rest of the realm might decide they want to renew hostilities anyway, forcing the leader to either put their lives at risk or be branded craven for putting their life before the dignity of the realm.
So as a more general topic which impacts all of this, people need to stop being so overly compromising and indifferent. By playing nobles we agree to certain rules of courtesy and respect, that doesn't mean we should all get along. Right now I'm playing a character in D'Hara who's a straight up pirate and part of a bastard lineage to boot. As of yet no one seems to care. I got one message asking why I was on the Western Continent and that's it. Someone should at least be grumbling about how my pillaging is a disgrace to our once proud realm.
