According to Rockstar, Arena War brings all-new game modes and a truck load of custom-built vehicles for you to drive and, presumably, destroy to your heart's content.
Ah, I remember why I left now...
"Enter Arena War, where ruthless gladiatorial combat meets the bleeding-edge of vehicular modification technology in one spectacular - and highly combustible - competition," an official post reads.
"Sign up and embark on an entirely new career under the stratospheric dome of the Maze Bank Arena, one that involves turning your opponent's brains into pulp on the steering wheel in the name of entertainment, courtesy of Alan Jerome Productions."
Arena War also features new Arena Points. The more you collect, the quicker you rank up. And the quicker you rank up, the more "toys to take into the Arena or out onto the streets" that you'll receive.
The update rolled into GTA Online yesterday on all platforms - Xbox One, PS4, and PC. Arena Wars is completely free, too, so don't worry about buying DLC or spending real-world money on in-game Shark Cards. The cars themselves may cost you a pretty in-game penny, though.
It follows Online's latest major update, After Hours, which was introduced in the summer. It welcomed celebrated DJs Solomun, The Black Madonna, Tale of Us and Dixon to the Los Santos nightlife.
These DJs helped you open night clubs and draw in cash-rich crowds - but really, what's better? Partying until the early hours of the morning, or smashing up cars in a dome? I'll leave that for you to decide.
What do you think about this news? Does Arena Wars sound fun? Do you still play GTA Online? Or are you fully onto Red Dead 2? Let us know.
Featured Image Credit: Rockstar Games