Recently, Portland Lesswrong played a game that was a perfect trifecta of: difficult mental exercise; fun; and an opportunity to learn about biases and recognize them in yourself and others. We're still perfecting it, and we'd welcome feedback, especially from people who try it. The Short Version The game is a combination of Pandemic, a cooperative board game that is cognitively demanding, and the idea of roleplaying cognitive biases. Our favorite way of playing it (so far), everyone selects a bias at random, and then attempts to exaggerate that bias in their arguments and decisions during the game. Everyone attempts to identify the biases in the other players, and, when a bias is guessed, the guessed player selects a new bias and begins again. The Pieces First, Pandemic. Pandemic is a cooperative game with a win condition and three lose conditions that are separate. It provides each player a list of available actions and then allows them 4 moves in which to mix and match those actions. Because of the combined win and lose conditions, players are constantly forced to decide between tactical and strategic objectives, with a strong emphasis on making it easy to choose tactically good moves at the expense of failing to win the game and thus losing by taking too long. Pandemic is a fun game, and it's a great game for people looking to stretch their brains. Obviously you want to be familiar with, preferably experienced at Pandemic before attempting Biased Pandemic. We did have one inexperienced player at Pandemic (out of 4) and that seemed to work okay, though it may have been harder for him than the rest of us. Enter the biases. Each player selects a bias. We printed out the biases listed here and used them to select our biases. One of our players just made a TOC for selecting biases. There happen to be 104 biases listed in that document, so a deck of cards combined with a coin flip allowed for bias selection. A computer's random number generator, dice, or any othe