I really like the idea of PVP, but it'd have to be orchestrated. Minecraft is a game that makes it entirely too easy to raid your enemy at midnight when no one is online. I'd suggest some form of plugin protection here, like to raid someone you must formally declare war, and when you've declared war you may only send as many people into the enemy nation as they have online. Something to prevent rampant afk raids and roflstomps.
We also don't have a massive player base, so I question how well it would work to fragment players inside the server. It turns from "No one's on the server" to "No one's on my nation" pretty quickly.
Good points. I'm still working out the details on pvp/raiding. For now, and with our smallish player base, we'd probably only have a handful of towns and not whole nations though as I said I intend opening this to the public as well so we may get some walk-ins. In fact until we get a decent population I may disable nation creation altogether.
Fragmentation happens anyway, I mean look at our current server. We have 3-4 distinct groups of people with bases in the overworld, water world, and mining world. Even if we didn't have those extra worlds, these people would have fragmented and forcing them to stay together would just result in unhappy people. Instead on the new server these people will be able to establish bases in the overworld by claiming and building towns. These towns will be visible to anyone because I'll be installing dynmaps so you can find your way around the server easily. The map will point out town borders, see who is online and allow you to chat with people on the server from the web, and will show protected zones among other things. It will be part of the server website and the site will have event announcements, etc.
By the way, is there a good webmaster out there who would like to assist? or a bukkit coder? or anyone really? This is a lot to do for one person but I'll get it done eventually.
Regarding Raiding, possibilities I can think of:
1. Raiding/pvp between towns/nations happens only on mutual declarations of enemy status. The Towny plugin allows towns to declare others as allies or enemies.
2. PVP, ie the killing of players by players, could happen at any time between mutual enemies.
3. Raiding, ie the destruction of property and stealing of lewts, is more complicated. I'm undecided between scheduled time slots and open raiding so long as a member of each town is online.
3a. Scheduled time slots are good because you know in advance when the raiding is enabled.
3b. Open raiding any time a member is online is alright, but what if that member is off mining or AFK? Its a touchy thing and would require some work.
Either way, raiding would be limited in destructiveness. You'd probably be able to break things like gates/doors, windows, 'soft' blocks like wool but I don't want one town totally leveling another. I'll give it more thought but it's certainly something I want in. If I had a dedicated bukkit coder I could do some cool stuff with this.