That's game

An phrase used and likely originating from pro gamer JESSE JO MARTINEZ, as early as 2006 in Guild Wars 1 or 2010 in Heroes of Newerth, when a game, match, round, or video game is near or about to be over, and you or your team are winning or losing. Usually it gets mumbled in frustration or in excitement over voice comms.

*Team A just did something stupid, giving Team B the lead. "That's game, we lost bois."

*Team A just did something really awesome near the end of a game turning the game into a win shortly after. "That's game. That's GG. We won this easy."

If said before a game is over in all chat, will be interpreted as you being either demoralized or wanting to concede, or confident you've already won the game.