The term edit war is a misnomer, but a catchy misnomer that is not likely to be replaced by a more apt term. In reality, edit wars on Wikipedia are reversion wars involving two Wikipedians, or sometimes two factions of Wikipedians. To wit, one Wikipedian edits an article, another Wikipedian reverts the article, and the first Wikipedian reinstates the changes that they made to the previous version, prompting the second Wikipedian to revert to the previous version. In the game of chess, three repetitions results in a draw. However, on Wikipedia, an edit war can go on for quite a while. This clutters the article history. And, it makes it difficult for uninvolved users to make edits, since participants in an edit war are unlikely to be careful about merging third-party changes.
A screenshot of an example of a massive edit war with one of the English Wikipedia's pages can be accessed by clicking here.
Which version would be protected?
Absent the intervention of a sysop, the protected version would be the first saved version that is identical to two previous versions. In theory, vandals could use automatic page protection to protect vandalized versions of an article, but sysops could easily intervene in such cases or, alternatively, automatic page protection could be restricted to versions of articles that have been saved by logged in users.
The alternative view
Don't let anyone tell you that the one correct spelling of colour was not worth getting in a 30-edit reversion war over—and make sure you make it known that anyone who tries obviously does not take Wikipedia seriously enough.
Tip, if you send a message to every sysop who is online, or just to all 100+ sysops, there is a greater chance that one of them will get on your side and protect your version. Alternatively, you can mention your complaints with the other user, random sysops, or all Wikipedians who disagree with you, on the village pump, the mailing list, problem users, or indeed all of those places. Eventually, someone will protect the page, or return it to the consensus version (see terminology in The Wrong Version), thereby allowing the other editors of the page to more quickly argue that it is on The Wrong Version.
It should be noted that pages relating to religion are always on The Wrong Version when they were last edited by someone who does not follow that religion, since this is evidence of 'pedia-wide discrimination against that religion. Similarly, if they were last edited by a follower of said religion, this is POV and must be corrected.