The act of talking nonsense or off topic due to the fact that the speaker is involved in a game, text conversation, or other distraction on their personal cell phone, computer, or gaming device. Game babbling often comes out when the person wants to be in the conversation, but does not want to give up their place in the game.
Tina, Joe, and Mary were involved in a conversation about current energy issues. However, as Joe was on his phone playing clash of the clans the entire time, when he interjected, "your oil in the car should be changed every 3,000 miles," he was ignored, because they knew he was just game babbling.