The event took place in Los Angeles and gave journalists, competitors and fans alike a chance to see what's in store over the next year for the gaming world, covering new technology, platforms, titles and online interactivity.
With so much to take in from this year's convention, Digital Spy has created a simple summary of the must-know highlights from the biggest pow-wow in gaming.
> E3 2012: Day One Round-up
> E3 2012: Day Two Round-up
> E3 2012: Day Three Round-up
Click through our picture gallery below to learn about the 20 most exciting revelations from E3, including the Nintendo Wii U, XBox SmartGlass, Ubisoft's Watch Dogs and more: