1. Each player starts with 20 life. If one player's life total drops to 0 or less, they lose.
2. You can "deck" your opponent, meaning his library of cards is depleted and he can no longer draw.
3. If a player has 10 poison counters on them, they lose. This was a half-formed concept in earlier sets and is now extinct.
4. Your opponent can concede, or give up. This is often done when a player realizes that his situation is hopeless and decides to spare both players the wait of playing the whole thing out.
Magic is easily the most prolific and well known CCG ever. While other games have came along that might sell more than magic, such as Pokemon or Yu Gi Oh, these eventually (will) disappear as the players mature and move on to Magic, which has endured for 10 years.
Mom: Where's your money?
Nerd: I just spent it on some maj
Mom: wow, that's so sad...
Often ridiculed/stereotyped by chads, along with D&D, Star Wars, and World of Warcraft as the epitome of geekdom. On the contrary, it is known to be played by anyone, and most gamers I've met don't fall into the stereotypes, and in fact, do have a life, have other interests, get laid, etc. Only people with no life like to make fun of people who play games like these. Irony at it's finest.
MTG Player 2: Aww, shit!
Random dipshit: What are you two fags doing?
MTG Player 1: Just got done playing a game of Magic, now we're gonna go hit up a kegger.
Random dipshit: Whaa!? I didn't know you nerds did anything else with your lives but play Magic the gathering
MTG Player 1: Yeah, crazy shit, huh? It's gonna be killer! beer and bitches everywhere! And the best part is everyone going is totally chill.
Random dipshit: No way! can I come?
MTG Player 1: Sorry, chads aren't allowed at this party.