The lowest common denominator for all World of Warcraft PvP is the desire for gear. It's the driving force behind most players' riding through the snow of Alterac Valley or running around pillars in Nagrand Arena. Those so-called Welfare Epics have inspired bloodthirst in many adventurers. Even carebears occasionally foray into the Battlegrounds just to get one or two epix to round out their gear. Personally, I've always believed that PvP is the most reliable and drama-free way of obtaining gear. With few exceptions, gear obtained through PvP is earned and deserved. No one has ever ninja'd a piece of PvP gear or lost one to a roll. No one has ever not had a piece of PvP gear drop from a boss. PvP gear is a sure thing. You put some time and effort into it and you're guaranteed a reward.
Contrast this with, say, raiding. I've run Karazhan enough to be Exalted with the Violet Eye several times over and I have yet to see the Mithril Chain of Heroism drop again (I passed on the first to my cousin's MS Warrior). I've shored up enough DKP to outbid anyone for the Pendant of the Perilous, but I've yet to see it drop in months of raiding SSC. On the other hand, the Veteran's Pendant of Triumph is a nice, shiny bauble that is always available (until 2.3, anyway...) and can be bought for a mere 15,300 honor and ten Eye of the Storm tokens. You can earn that much honor in about half a day of playing AV during the AV weekend. Ten Eye of the Storm tokens is easily earned -- most casual PvP'ers have 100 of each BG token stored in the bank, anyway. Granted, PvP-earned gear is most assuredly not the best gear for PvE (unless, of course, you're a Retribution Paladin) because so many item points go towards Resilience and Stamina; however, they're still pretty darned good. In fact, pretty much the only players who can't benefit from PvP gear directly are tanks. Even my carebear wife's Holy Priest, whose only remaining blue item is her wand, will be getting the Vengeful Gladiator's Baton of Light when Season 3 goes live after amassing Arena points because she didn't want anything. All those games where I persuaded her to heal for our team ended up being worth it after the Blue Diamond Witch Wand refused to drop from the Crone (who hardly ever showed up to begin with) after months of trying.
Excepting low to mediocre Arena ratings, PvP is arguably the fastest, most reliable source of epics in the game. Crafted items are a close second, but those cost you gold. PvP gear is practically free.
Some people, on the other hand, PvP simply because it's fun. I don't know about everyone else, but I get a great rush from PvP. Excepting unprovoked griefing, I consider PvP to be a competition similar to sports. I used to compete on collegiate judo and fencing varsity teams and WoW PvP brings back some of that competitive thrill without -- for better or worse -- the physical exertion. PvP is like a mini-game within the game of Warcraft itself, much like fishing or the Simon Says quest in Blade's Edge Mountains (or even, as in my wife's case, the Auction Houses). Battlegrounds, in particular, are often a welcome distraction from the occasional doldrums of WoW. It's PvP without the pressure, where I often use a death as a cheap way to get back to full mana and health. Arena PvP is at the other end of the spectrum, where dying often spells defeat for your team. Battlegrounds is to streetball where Arenas is to the NBA. Both are fun but demand different levels and styles of play. Non-objective world PvP falls somewhere in between. Gankage is technically PvP, since you're obviously going against another player, but if that player isn't into PvP, is wearing farm gear, or to any degree unwilling, then I personally don't see it as a real challenge. There's no strategic value to ganking; it doesn't advance any objective like Battlegrounds, Arenas, or objective-based world PvP like in the Bone Wastes or Halaa. More often than not, it's just a case of stroking one's epeen. Some people get their kicks from that, I suppose, so more power to them.
Personally, I prefer my PvP to have some form of objective, a real challenge. I find little pleasure in striking down a player who's at half life fending off three mobs. In a BG or Arena, you deliberately pick off the weak because it's the right thing to do strategically. You can be pretty sure everyone who's in those PvP zones know what they signed up for so it's all fair game. When you clash mid-field in Warsong Gulch or capture towers in Hellfire Peninsula, for example, you're trying to achieve an objective. Capturing the flag by evading all your pursuers is a great example of what Sun Tzu considers "supreme excellence". It isn't always applicable to WoW PvP, but according to The Art of War, "supreme excellence consists in breaking the enemy's resistance without fighting." Of course, he just might have been referring to Druids. Seriously, though, achieving one's objective in the fastest, most efficient manner is what I'd consider the ultimate achievement in a PvP environment. The eight minute 3-0 WSG game or the five minute 5-0 Arathi Basin is the perfect example of a successful military campaign. Nobody enjoys a three-hour WSG still tied at 0-0. Remember the gruesome era of thirty-hour AV games? When I played Airsoft, my best games were when I managed to tag opponents with a tap on the back, or a knife kill. I saved pellets, didn't hurt anyone, and achieved team objective. Is that considered PvP? Oh, absolutely. Remember what Mr. Miyagi taught Daniel about training in Karate? On the lake, Daniel asks Mr. Miyagi about his past fights and about Karate. The student proclaims, "Karate's fighting. You train to fight."
Brows furrowed, Miyagi asks, "that what you think?"
Reflecting, Daniel responds, "no."
"Then why train?"
"So I won't have to fight."
Of course, this is the World of Warcraft, and nuggets of movie wisdom don't always apply. Sometimes, you do have to fight. On those occasions, enjoy it. Perhaps the most fun aspect of PvP for me is that I get to exercise certain class skills or talents I might otherwise ignore in PvE encounters. In raiding, there are particular strategies to defeating every mob, every boss. There are optimal spell cycles for DPS or certain key spells you throw as a healer. It takes skill to perform these tasks well, let's make that clear, but in PvP, every encounter is different. As Vims pointed out, there are a crazy number of potential matchups with the nine classes in the game. Those formulas didn't even include specs, which increase those numbers exponentially. For example, you can't deal with a Frost Mage in the same way as a Fire Mage. The double ice block makes them extremely resilient in PvP, so you're better off focus firing on someone else, etc. Compound this with the infinite combinations of gear, terrain, player skill and latency, and you're guaranteed that no two PvP encounters will be the exactly the same.
Ultimately, I find PvP to be the one of the most fulfilling aspects of the game. In order to truly excel in it, one needs to learn how to use every skill or talent available. Renowned Japanese swordsman Miyamoto Musashi wrote in Go Rin No Sho or the Book of Five Rings that one must not be content to die without using all the tools at his disposal. This couldn't be more true in PvP. PvP gives opportunity to use everything -- your spells, the lay of the land, and your allies or lack thereof. Utilizing LoS to shut down players in Arenas; using Far Sight to scope out opponents hiding behind pillars to fill out your Proximo list; casting Unending Breath to go all Navy SEALs on the Stables in Arathi Basin... the list goes on. PvP is fun because it stretches your skills as a player, pushes you to be creative and of course, there's the adrenaline rush.
Whatever your reason for playing PvP -- it's usually either or both -- this column will attempt to explore the intricacies of WoW PvP. From applying The Nine Situations from The Art of War to the Battlegrounds; to listing the less-commonly used skills and talents for PvP; to what I like to call gearspotting, or assessing your opponents' relative strength based on a cursory look at their gear, let The Art of War(craft) be your companion to PvP goodness at WoW Insider. Next week, we'll take a look at the new and (supposedly) improved Alterac Valley of 2.3.