The convention used up all 10 floors of the library.
Gamers enjoyed traditional video games together but there was so much more.
Local artists shared their creative work on one floor, there was a board game competition on another and even a Cosplay contest.
"It's so exciting. We see entire families come to this event. I think for me that inter-generational piece of kids being able to share their love of gaming with their parents, siblings coming together," said Taylor Bayless with the Chicago Public Library.
"You can make friends and you can also team up and also use different types of moves," said Tristian Frazier who attended the event.
Organizers said this was the first year all floors of the library were utilized.
Prizes included Nintendo products gaming headsets and even an Xbox mini fridge.