The difference becomes even clearer with MMOGs, which are often played by both casual and hardcore gamers. PvPers are almost always considered more hardcore, and they certainly consider themselves more hardcore. Does it make sense to call someone who raids three hours a night, four times per week, casual? Not to me, but "PvE carebear" is a term which gets tossed around by "hardcore" PvPers. Of course, another term often used by PvPers in any online game is "rape."
The use of the term rape, as in, "I totally raped that druid," or "We raped those noobs in Call of Duty," makes the implicit sexual violence of the hardcore gamer explicit. It is not enough to defeat the enemy in a fair fight. It is not enough to kill the opposing player's avatar; it must be rape, the worst action that someone can do to another in our society (short of killing them). Their manhood is supposedly crushed, and they are rendered defenseless and pathetic. It is the ultimate form of dominance, combining violence, sex, and identity. And the winner gets to feel like their "e-peen," the electronic penis, is bigger, better, and stronger.
Terms like "rape" and "e-peen" are thrown around so much in online games that one has to wonder if the speakers are in on the joke. They may not say it academically, such as declaring that competitive multiplayer gaming is often a battle for possession of the phallus, and they may not even wish to acknowledge the inherent sex and gender basis of the terms when baldly confronted with it, as I'm doing here, but they can see through the bullshit. Real gamers, hardcore gamers, are using those terms to express their masculinity, not to make any particular claim about the nature of the game. But the expression of masculinity says nothing directly about their genetics or their genitals, but instead, their performance. It's all about how they want the world to perceive them. The "e-peen" is that academic phallus, because it's entirely performative.
This is not to say that everyone or even anyone who uses the word "rape" to say that they beat someone in an online game is a rapist, a would-be rapist, or any kind of bad person. I've played World of Warcraft with wonderful players who use the term casually, as its meaning has become so diluted that it just means "defeated in combat." The point instead is that the term has caught on because it denotes both success in combat and a performance of masculinity. The popularity of "teabagging" opponents' corpses in PvP games works along the same principle. There are other actions which could be taken to taunt an opponent - if you can crouch in a game, you can almost always jump as well - but the one which can be interpreted as an act of aggressive male sexuality is the one that caught on.
Perhaps this dismays you, gentle reader. Perhaps it upsets you, not-so-gentle reader. It can be discomfiting to have seemingly innocuous terms labeled as sexist and violent code words, which leads to demanding questions along the lines of "What is to be done?" To be honest, I don't think there's anything that's going to make this hardcore maleness go away. It taps into the same social vein as physical sports, frat and military hazings, pro wrestling, and muscle cars. These outlets exist and have existed for decades, for better or worse, before that yammering 14-year-old called you a homosexual while playing Halo 3. Certainly, games allow for social interactions where such bursts of testosterone poisoning wash over people who wouldn't normally be ready for such immersion.