The Biggest Continuity Errors And Plot Holes In 'Back to the Future'

Voting Rules
Vote up the most story-breaking paradoxes in the Back to the Future movies.

While the idea of time travel is something that fascinates people, movies based on this premise always suffer from one particular problem: paradoxes. Paradoxes plague even the best time travel films. Anytime a character has the ability to go into the past, it opens up endless possibilities of all sorts of problems. Even the most famous movies have a whole mess of plot points that simply don’t make any sense when you look at them closely, none more so than the paradoxes in Back to the Future.

Despite being arguably the most famous time traveling movie of all time (at least until the inevitable reboot gets made), Back to the Future has its fair share of problems. In fact, the movie is packed with logic-breaking paradoxes, thanks to the fact that Marty and Doc can seemingly travel to any point in time. Almost every time travel story warns against tampering with the past and with good reason. Even the smallest change can massively alter the future and the characters from this series seem to enjoy nothing better than modifying the world around them.

Listed here are the biggest and most damaging Back to the Future paradoxes. They don't just introduce plot holes; they negate the entire series in one fell swoop. Whether they were caused by a misunderstanding of the laws established in the first movie or due to an oversight by the writer, each of these paradoxes is big enough to erase everything that happened in the three movies. Check them out below and vote up the paradoxes that wreak the most havoc on the franchise. 

  • 1
    1,241 VOTES

    How Do Marty’s Parents Not Recognize Him?

    One of the most obvious problems with the first Back to the Future film is the fact that Marty’s parents do not recognize him after he returns to 1985. This is remarkably strange, considering the huge impact that Marty had on their lives in 1955 in the guise of Calvin Klein. 

    While it is perfectly acceptable for people to forget individuals they meet after 30 years, this wouldn’t apply to Marty. Although he was only with his parents for a brief time, he was a major driving force in getting them together in the first place. Combined with the fact that his mom had a crush on him and that he made a memorable performance singing “Johnny B. Goode,” it would seem almost impossible for them to forget what Calvin looked like.

    Why, then, do they not question the fact that their son looks exactly like the man they met in 1955? Anyone else would think it was at least a little strange that their child bore a resemblance to a mysterious figure who helped kickstart their relationship.

    1,241 votes
  • 2
    880 VOTES

    Doc Should Already Know He Was Going To Get Shot

    Thinking about the events of Back to the Future III logically for a second means that the entire film should never have happened in the first place. This is because as soon as Doc and Marty in 1955 discover that Doc in 1885 is going to be killed, that knowledge should have been directly transferred to the Doc that was going to be shot by Tannen.

    The simple reason for this is that the Doc from 1885 is actually an older version of the Doc from 1955. Anything that he learns in 1955 should be etched into his memory from that moment and passed onto the Doc who is living in the Wild West. Although he is living in the future, the 1955 Doc is the younger version of the same person, meaning that the one living in the past should have the same memories.

    This would negate Marty ever having to travel back in time to 1885, as Doc would know the danger he was in and simply be able to pay the $80 to Tannen or skip town. None of the events in Back to the Future III need to take place as, logically, Doc should know he is going to be shot as soon as Marty tells the younger version of him. 

    880 votes
  • 3
    777 VOTES

    The Time Machine Should Have Ceased To Exist When The Doc Was Committed

    One of the first things that Marty and Doc learn when they travel back to the alternative version of 1985, where Biff is now a mega rich overlord, is that the inventor was committed several years before. Presumably, this was so that he could not interfere in Biff’s plans and prevent him from earning his ill-gotten wealth.

    This would mean that the time machine was never invented in the first place. After all, Doc cannot construct the DeLorean if he is imprisoned with no access to the tools and parts he needs. Going by the strict rules established in the first movie, this would mean that the DeLorean time machine should no longer exist in the timeline.

    This should essentially stop the original events of 2015 from ever happening as they did. Biff would never be able to steal the sports Almanac and bring it back to his younger self in 1955, as the time machine wasn’t built in 1985 to allow time travel into the future in the first place. 

    777 votes
  • 4
    701 VOTES

    Marty’s Kids Shouldn’t Exist In The Future When He Travels To 2015

    It is firmly established in the first Back to the Future movie that any changes in a timeline immediately begin to alter the world. Although people aren’t erased from history instantaneously, the effects do start to happen as soon as history is changed. This should have consequences in the second movie, as Marty and Jennifer should never be able to meet themselves or their kids when they travel to the year 2015.

    The laws that appear to govern the Back to the Future series tells fans that once Marty and Jennifer are removed from the 1985 timeline, any future that depends on them being present during that time should disappear. If the two are not in 1985, they cannot age and naturally make it to 2015.

    If that is the case, then it should be impossible for Marty and Jennifer to meet themselves or their kids. After all, those future people only exist if the pair are part of the 1985 timeline. By traveling to the future, they remove themselves from that reality and no longer exist in 1985. Therefore, their future selves should no longer exist, either.

    701 votes
  • 5
    734 VOTES

    Marty Should Not Know About The Lightning Strike As It Wouldn’t Have Stopped The Clock

    The way that Marty is able to escape 1955 and return to his own time in the first film involves him knowing about the time and place of a lightning strike. This is the only way to generate the energy needed to power the DeLorean. Marty knows about this because the lightning strike stopped the clock when it hit the timepiece in 1955 and he is given a flyer about the event before traveling back in time.

    However, Doc and Marty effectively stop the clock from ever being hit with lightning. Their plan involves diverting the electrical energy directly into the time machine, rather than the clock. This means that the clock should never have been hit and would not have stopped working. 

    If the pair stop this from happening, as they do in the movie, then no one would ever know the exact time and location of the strike. The fact that the clock would still be working perfectly would mean Marty would never get the flyer in the first place. Without the flyer, he wouldn’t know when the lightning strike was going to happen and would be unable to return to the future. 

    734 votes