“Intermittent reinforcement,” he said. “My friend Matthew, he leads our guild, he told me about it. It comes from experiments with rats. Imagine that you have a rat who gets some food every time he pushes a lever. How often do you think he pushes the lever?”
“As often as he’s hungry, I suppose. I kept mice once — they knew when it was time for food and they’d rush over to the corner of the cage that I dropped their seeds and cheese into.”
“Right. Now, what about a level that gives food every fifth time they press the lever?”
“I don’t know — less?”
“About the same, actually, After a while, the rats figure out that they need five presses for a food pellet and every time they want feeding, they wander over and hit it five times. Now, what about a lever that gives food out at random? Sometimes one press, sometimes one hundred presses?”
“They’d give up, right?”
“Wrong! They press it like crazy, All day and all night. It’s like someone who wins a little money in the lottery one week and then plays every week afterward, forever. The uncertainty drives them crazy, it’s the most addictive system of all. Matthew says it’s the most important part of game design — one day you manage to kill a really hard NPC with a lucky swing, and it drops some incredibly epic item, and you make more money in ten seconds than you made all week, and you have to keep going back to that spot, looking for a monster like it, thinking it’ll happen again.”
“But it’s random, right?”
“I’m not sure,” he said. “Matthew says it is. I sometimes think that the game company deliberately messes up the odds so that when you’re just about to quit, you get another jackpot.” He shrugged. “That’s what I’d do, anyway.”
“If it’s random, it shouldn’t make any difference what you do and where you play. If you flip a coin ten times and it comes up heads ten times in a row, you’ve got exactly the same chance of it coming up heads an eleventh time than if had come up all tails, or half and half.”
from cory doctorow: for the win, another great read that for reason i am taking ages to finish reading on my iPad.