Do I need to sign a legal agreement with Epic Games before I commercialize my game?

Hi, my name is Eric and just a few days ago, I opened a Kickstarter (which hasn’t launched yet) to fund a computer I would like to purchase to allow me to develop a horror game. Before I start development on the game or the Kickstarter, I was wondering if there are any legal agreements or obligations if I wish to create the game in Unreal Engine 4 and then commercialize it.

Thank you very much,

Best Regards,
Eric

There won’t be any legal aggrements need to sign, as mentioned in the epic site or while downloaing enigne itself mentiones the terms and conditions about the 5% revenue cut after your game made $1,000,000

Check this link for clarificaiton