Phrase used in the internet gaming community at a player when he/she displays frustration over the mechanics of the game in question. Its meaning is to tell the frustrated player that he/she should educate his/herself on the basic skills required in the game, so that they may perform better in similar situations should they present themselves in the future.
Evolved (or devolved) from the phrase "Learn to play".
Often shortened even moreso to "l2p" or "L2P".
Frustrated Player: "That's not fair! Rogues can just pop out of vanish and stunlock me until I'm dead."
Rogue: "that's fine, lern2play."
Frustrated Player: "What the hell?! All you do is camp in the shadows and headshot me from far away!"
Sniper: "lol, lern2play n00b."