This definition originated, and as I type is only commonly used in the MMO game Realm of the Mad God.
The New Player Experience, or NPE, is a play-style in Role Playing Games that involves creating a character who is played without support from the player's main characters, or support friends that may offer.
Friend of NPE player: "The boss dropped some better armor than you are wearing, do you want it?"
NPE player: "Nah, I can't man. This is my NPE."
Friend of NPE player: "But your gear is garbage! Argh!"
NPE player: "Yeah, but it is fun to start over. Goblins take more than 1 hit sometimes."