10 Dumbest Sci-Fi Movie Decisions (That People Survived)

After surviving his misadventures in 1955, which nearly resulted in his being erased from existence, Marty tempts fate once more in the sequel. You have to give Marty some credit with this decision because it's one that almost anyone in the world would do, but that doesn't make it a smart move.

He purchases a sports almanac from a shop, and with it, he hopes to win some serious cash. It's essentially financial planning for when he returns to his present (1985), but he didn't think hard enough about how he would change the future, so Doc Brown reminds/reprimands him.

After the Doc ditches the Almanac, he assumes all is well, but Biff wasn't far behind. Even though Doc and Marty couldn't have known Biff would steal the book and borrow the car, creating a new timeline where he elevated himself to Trumpian levels of monetary debauchery, they should have taken more precautions about mucking up their timeline.

When they return to the present and find it completely different, thanks to Biff's time travel shenanigans, Marty is nearly killed on three separate occasions. Despite having the odds stacked against him, he survived his principal's shotgun in his face, the driveby that riddled the house with bullets, and Biff's attempted murder.