I don't think anyone had a huge problem with my gang war system, except for the inherent need for my active involvement since I made a desktop app fed (by hand) from the forum rather than something fancier and automated. It even had approval from HQ at the time.
One group declares their intent to go to war with another. If the declaration is reciprocated, the hounds are loose and anything goes - it's left to the two groups to work out what's "okay" for them. Using /report DM against a member of the other group is a no go since it's allowed.
If the other group does not reciprocate, nothing changes. The two groups may not engage in a war.
If one group pulls out of the arrangement, after maybe 24 hours (enough time for anyone to check and find out) the war is called off and you return to normal.
If this were done elegantly, probably with some kind of web panel, then it could work. It does however rely on an understanding across the entire admin team that this is how it works, and that they have an easy way to quickly look up if a fight is valid. It needs full support from literally everyone to work. It requires groups that are at war to communicate with each other over what goes, and if a personal rule is broken it requires the group leaders to handle it.
It's one end of the spectrum between structured, documented wars and free RP (that is, no system at all). The latter is theoretically better but some groups are liable to abuse /report when they lose, and it raises a lot of issues over what constitutes a "fair" war and obviously different admins will have different opinions on what counts as DM. There's no particularly "best" way to do it, some people will like the structure and others will not. It does add another responsibility for admins, although in theory also makes these reports easier to judge.
Or instead of all that, maybe people just shouldn't be such sore losers and grow up a bit, but I guess that's asking a lot.
