Play Test (Playtest): A process by which a game designer tests a new game for bugs and design flaws before releasing it to market, by having others play the game while the designer observes. While game flow, scoring and playtester feedback are valuable information, the most important data from the play test comes from the body language, table talk and unconscious behaviors exhibited from the players. Do the players lean away from the game space, do they look at their phones between plays or disengage so much that they need to be reminded that it is their turn? Do they lean in toward the play space, discuss the play in excited terms? After the game do they analyze the game spontaneously and discuss better play techniques or do they call out areas where the game seems broken?
Often, the best feedback is unprompted and unspoken.
Rattle Test: A early, informal test where the designer runs through the game, typically as a solo, to see if anything is overtly broken; to see if anything ‘rattles’. If something is discovered, more design work is needed before formal playtesting is done.