Published , by Ozzie Mejia
Published , by Ozzie Mejia
For years, GGPO (Good Game Peace Out) has been one of the most recognizable acronyms in fighting games. It's a licensed program specifically integrated into the netcode for arcade and fighting games, particularly peer-to-peer ones that require fast response times. It has been a godsend to many fighting games, both in the indie space and in the mainstream gaming world. And now, creator Tony Cannon has made it free for everyone.
Late Tuesday evening, EVO co-founder Cannon announced that the GGPO Rollback Network SDK would be made available under the MIT License. This essentially makes it free for anyone who wants to use it for commercial and non-commercial purposes.
"In rollback networking, game logic is allowed to proceed with just the inputs from the local player," explains the GGPO website. "If the remote inputs have not yet arrived when it's time to execute a frame, the networking code will predict what it expects the remote players to do based on previously seen inputs. Since there's no waiting, the game feels just as responsive as it does offline. When those inputs finally arrive over the network, they can be compared to the ones that were predicted earlier. If they differ, the game can be re-simulated from the point of divergence to the current visible frame."
Games that have utilized GGPO netcode to great effect include Killer Instinct, Skullgirls, Street Fighter III: 3rd Strike Online Edition, Marvel vs. Capcom: Origins, Divekick, Lethal League, Brawlhalla, and Cannon's own project, the now-defunct Rising Thunder. Many newcomers to the fighting game scene, like Fantasy Strike continue to look to GGPO netcode as an effective way to help incorporate online play.
If you're looking to implement GGPO into your prospective fighting game or arcade-style throwback, give it a look on GitHub.