Step 1 : Introduction to the question "Which board game features the Pop-O-Matic bubble?"
Trouble is a board game in which players compete to be the first to send four pieces all the way around a board. Pieces are moved according to the roll of a die. The most notable feature of Trouble is the "Pop-O-Matic" die container. This device is a clear plastic hemisphere containing the die, placed over a flexible sheet. Players roll the die by pressing down quickly on the bubble, which flexes the sheet and causes the die to tumble upon its rebound. The Pop-O-Matic bubble produces a popping sound, and allows for quick die rolls.