Even up the numbers. Needless to say, ganging up on one player isn't fun at all. That's just bullying. Conversely, against much lower-level players, going up against many isn't the same as going up against another player of similar level. Eighty-five level 1 characters aren't equivalent to one level 85 character, and they would all get slaughtered if a max-level character decided to unleash everything against them (but you have to admit that it's a fun thought). Because abilities scale to level and because hit factors into the equation, a higher-level character has an insurmountable advantage against very low-level ones, so numbers don't equate to an even fight.
The fun thing about world PvP? Everyone gets to join in. I don't agree with engaging another player with superior numbers, but I'm all for calling for help when the fracas starts. The best world PvP has always been the massive kind -- and not the carefully engineered ones courtesy of Wintergrasp (and soon, Tol Barad). I'm certain many PvPers still wistfully recall the days of skirmishing between Southshore and Tarren Mill, an event that often grew from a few players getting in each others' way while questing to a battle involving a huge chunk of the server's online population. That kind of spontaneous PvP comes from the need to even up the numbers as well as a genuine desire for some unabashed PvP. It will probably never happen again on that scale, so cherish the little skirmishes that happen now and again. Don't be afraid to call your friends.
Don't rub it in
This rule, above all others, should be called the "don't be an asshat" rule. Personally, I don't find teabagging amusing. Fortunately, I find that few players do this nowadays, but it's simply one of those things that demonstrate a lack of manners. Win graciously and on even terms, and you'll find that opponents will grow to respect you as a competitor. Kill them often enough under fair conditions, and you will be remembered and recognized for the right reasons. On the other hand, actions such as teabagging are guaranteed to generate a lot of negativity. I'm all for PvP, but I'm not a big fan of gloating or, worse, the emote equivalent of profanity. Celebrating your victories with maturity and even humility -- especially with a gracious nod to opponents such as a /salute or /bow emote -- are always great ways to finish an engagement.
I always tend to have the highest respect for opponents who fight on even ground and approach the battle with dignity. Maybe I've watched Wesley and Iñigo Montoya duel too many times, but I think there's always a place for mutual respect. As much as I'd like to beat every single opponent I come across, I particularly enjoy battles with opponents who manage to defeat me and defeat me well. They're challenging instead of infuriating. They inspire respect rather than contempt. Although in-game emotes such as /spit and /rude are fair game, used cross-faction, they don't send the message I'd like my opponents to receive. My best experiences in the game have been when opponents created toons on my faction just to tell me they enjoyed battling with me. You wouldn't do that to players you despise. You're more likely to block them, harass them or put them on your guild's Kill On Sight list.
Anglers are off limits
No, really, it's just common courtesy not to attack fishermen. First of all, they don't have their main weapon equipped, and if they're a class that's dependent on their weapons for attacks (such as warriors or rogues), then they're starting the fight at a severe disadvantage. Second, anglers aren't bothering anyone and their willingness (or lack thereof) to PvP is demonstrated by the fact that they're completely exposed and without their weapons (and in some cases, equipment, such as when they wear their fishing hats). Attacking anglers simply isn't cool. On the other hand, swimming in their pools isn't cool, either, but at least you'll get your intentions across.
There are no rules
Despite all that I've written, however, you must remember that in the end, there are no rules. Although I generally follow these guidelines whenever I go around Azeroth, I don't expect other players to have the same code of honor. For one thing, if everyone refused to attack first, there'd be no world PvP, and that would be exceedingly sad for me. I expect enemy players to attack first and welcome the challenge. It gives me a reason to fight. Not that anybody really needs one on a PvP server, but at least nobody can say I griefed them (which really makes me wonder how I get on some guilds' K.O.S. lists -- but hey, you can't win 'em all).
None of these rules apply, and the honest truth is that nobody really cares if you follow them or not. As unfair as it sounds, you will almost never get a reputation for being an honorable fighter, no matter how hard you try, but you're guaranteed to get a reputation for being a filthy one if you engage in constant griefing and other less savory behavior. The latter also seems to be a motivation for some players who would rather play in infamy rather than anonymity. Playing fair is a personal choice, as with most of the things we do in this game. For the most part, do it for your own peace of mind. Unless you're the kind of player who enjoys uneven contests, a simple code of conduct should help you enjoy your time on a PvP realm without disrupting the way other people play.
Zach delivers your weekly dose of battlegrounds and world PvP in one crazy column. Find out how the Cataclysm talent tree redesign affects PvP, how sub-speccing will work at higher levels in the expansion, and how the new Azeroth will affect world PvP. Visit Blood Sport for the inside line on arena PvP.