A form of gaming that involves sitting on one's ass until 3 AM playing hardcore games like Japanese RPG's from 1991 and drinking so many energy drinks you will be diagnosed with diabetes and heart failure at your autopsy.
The people who do this are generally called "gamers" or "hardcore gamers", and are guaranteed to be virgins until the age of 42. They then defend themselves on game forums (not in real life because they have no one to talk to, hence the word, "loser") by claiming gaming is a sport and guys like Walshy are "cool".
Any one who has been outside in the last week hates hardcore gamers.
Greg: Yea, man, that hardcore gaming session last night was totally leet, I doused 4 cans of monster and I also got past the lord of the orcs in fantasy rebellions 17. It was fun, yet challenging at the same time.
Normal Person Who Steps Outside Every Once in a While: Dude, get a fucking life.
"Hardcore gaming" is an activity that involves learning every possible maneuver/ability/stage in a videogame not only to win, but to win efficiently, making the fewest mistakes and taking the least amount of time to win. Winning may be collecting items, downing opponents, completing levels etcetera. Winning can be any combination of these goals and may vary depending on the game.
Spending countless hours playing a game may be a result of hardcore gaming, but is not a requirement. Simply playing a game without striving to improve or master the game is not hardcore gaming. That would be casual gaming.
After or near mastery of the game, the player can be called a hardcore gamer for the said game.
(Danny is positioned in front of his television with a controller in his lap.)
Mary: Why is Danny repeatedly playing the same racetrack over and over with different cars? There are many more tracks in that game!
Austin: Well, isn't obvious that he's trying to learn the track and find the car best suited for that track? You don't know much about hardcore gaming, do you Mary?