On April 27, the entire Marvel Cinematic Universe will finally reach its climax (sort of). The Mad Titan, Thanos, is set on acquiring the Infinity Stones, and Earth is standing in his way. Everyone is joining together to stop Thanos in an epic showdown that has been ten years in the making. How does a proper fan get even more pumped up for this movie or give a friend a crash course in the MCU? Watch the other movies, of course! But nobody has time to watch 18 movies in a few days unless they took vacation time to camp out in front of a theater.

That being said, here are the MCU movies that must be seen before watching “Avengers: Infinity War."

The early days of Phase One

First, watch "Captain America: The First Avenger," since that was the first time we saw an Infinity Stone. Yes, "Iron Man" was the first movie in the MCU, but there’s literally just days until Infinity War, so a little crunching is required. Second, watch “Marvel’s The Avengers,” which starts the union of the heroes and introduces Thanos and his eventual plan to kill most of the universe.

The expanded Phase Two

If you want more of Loki, you are in luck, because "Thor: The Dark World" is next. It’s only on here because the Reality Stone is pivotal to the plot and lets fans know of its whereabouts.

Tired of Cap? Too bad, because “Captain America: The Winter Soldier” is up next. Bucky’s reappearance is pivotal to all of Phase Three and the fall of S.H.I.E.L.D. changes the whole Avengers operation.

Next up is the hilarious “Guardians of the Galaxy.” Thanos gets screen time, the Power Gem is key, the Infinity Stones are explained, a new team is added, and the entire universe is expanded.

Last out of Phase Two is “Avengers: Age of Ultron.” Is it the most beloved by fans? No. However, this movie redefines Tony and sows the seeds of dissension that lead to Civil War. Plus, the Mind Gem is center stage and the Vision is added to the MCU roster.

The latest Phase Three

As we get into the more recent installments, “Captain America: Civil War” is the first of Phase Three.

Tensions have built, especially over Bucky and Avenger politics, and the division when the dust settles is going to be important in Infinity War. The last Infinity Stone that’s been shown in the movies so far is the Time Gem, which is Stephen Strange’s favorite toy in “Doctor Strange.” That’s second to last, and that should give fans a total recap of the Infinity Stones and their locations.

Finally, fans can treat themselves and watch “Black Panther” again. Wakanda is going to be the site of major scenes when Thanos attacks and possibly the site of the deaths of some of our favorite heroes.

If you have time, watch more of the movies, but these ten will allow everyone to mostly keep up with the events of "Infinity War." Half of the movies seems much more manageable than 18, and who really needs an excuse to watch them again anyway?