The PvP forums. Ah I can almost smell all the hate and grief this sub forum has given rise to. It has always amused me and frankly surprised me how vocal the care bear population was on DDO, not to mention disgusted. Mostly because so many would tear down PvP while claiming with great passion that there never was any PvP around the table top.
This struck me as laughable beyond the capability of any words to convey. You see the reason why is every single moment of a Pen and Paper session is Person VS. Person. Players are trying to outwit DMs, and if being properly role played usually each other as well.
From the paladin that takes offense to the rogues lies, cheating, and stealing to the barbarian who decides to cave in the brains of the wizard the moment he goes to sleep, are all examples of common PnP PVP.
Another example is the older editions classes often having requirements to gaining a level often included going to defeat another member of the same class of equal or greater level( old school AD&D kensai I am looking at you my precious), and this was always a great time for DMs who got to spend time practically making thier own character, with the soul intent of using it to face off in a one on one duel.
Always was an extra special test of a DM to, does he abuse DM status to make an unfairly enhanced villain, or does he succeed in the ultimate test for a DM and keep himself bound to the same limits as his players, and prepare a character he may invest a fair bit of time in, even envisioning him as a potential new NPC rival. Finally when the moment comes and they face off, its often so nerve wracking for the player, wondering if its a PK build created just to cut his life short. Even as the DM if playing fairly strives to provide an action packed and cinematic scene for all to enjoy whether they are involved directly or just watching.