How to sneak into a movie theater

Keep in mind that at most theaters the shift will change around 5:00 so if you go just before then the new shift will not recognize you, so you will be free to hop to another movie (Thanks to Dave and Big Rob for that tip).

Use the rest room
There are some theaters where they will let you use the restroom because there are no other restrooms in the area, just go in while it’s really busy and when you come out, go down the hall and into a movie . If it is busy enough then you should be able to go un-noticed.

Use the phone
This is the same principal as the restroom, you just need to time it right, if about 4 movies are letting in at the same time the should be enough diversion that you can slip past the workers without a problem.

Buying popcorn
This one is a bit of a stretch, you can ask the door person if you can go in to by some popcorn. We all know that movie popcorn is the best so they will usually let you do this but unless it’s really busy then you can’t get lost in the crowd.

Have a friend bring you a ticket stub
If you are in a group of say five then you can get away with only buying three tickets. Three people buy tickets and go sit down, two of those people stay and the third takes all three ticket stubs and gives two to the fourth and fifth people, keeping the third stub for himself. This will work best when there are 2 or more entrances to a theater so the same door guy doesn’t see you going in and out. Note: This works because you only need a ticket stub for a current movie to enter a theater. also Chris says "the whole buy a ticket and slipped it between 2 people does not really work. in my facility as well as many others, the two halves of the ticket are different. i train my floor man to only take one side."

Ask for a stub
While I don’t suggest this next technique I have seen it done. You ask people in the movie for ticket stubs and then take them out to your friends. I can’t honestly suggest that you try this because there is no way to tell who you are asking for a stub, it could be an off duty theater employee and that would end your hopping real quick.

Sneaking in the back door or through a theater exit
Listen carefully to this one, THERE ARE CAMERAS at the back doors and ALARMS on the theater exits. It is far easier to sneak in the front then it is through the back. DO NOT SNEAK THROUGH THE BACK DOOR.

Follow a wondering child from Reed
Little kids have a tendency to wander around and run past people at the door, it's only natural for a parent to run after them. If the child runs out of view from the person at the door then you should be home free.
This one could work but it is sometimes hard to get kids to wander where you want them. Note: Please use children that you personally know (your own, a younger sibling, the neighborhood kid), do not go bribing strange children with candy to do this for you or someone will think you are trying to poison then or abduct them and you could get put in jail. If you try this I will find you and kick you in the groin so don’t do it.

Get a free ticket Jameson
If you live in a big city, find out where and how to get all the free passes to screenings you can. If that movie is like "Attack of Gina Davis 2" or whatever, no problem -- because once you're in, just go into whatever you want.
This is an excellent way to get into a movie theater. Listen to special radio announcements and the local news segment on the morning news.

Old ticket stubs Chad
Just use your old stubs. It really works quite well, especially when they are the line is long and they are letting in several patrons. Keep this in mind. When you are a 15-18 year old theater worker and being paid a little above minimum wage to tear tickets, you could care less about people sneaking in--I know that I did. Usually, just flashing a stub is enough to get you in. If it's real busy too, just hold up your stub outside of the line and step over the rope. The pimply-faced kid tearing tickets isn't going to stop to grab your stub and double-check it.
This really depends on two things. One is the guy checking to stubs a jerk? If it was I then I would probably check the stub because that's how I got my jollies. Two is it really busy? If it's super busy then they can't really run after you because more people are coming though the door with tickets and you are in.

Another trick with old stubs Kit
Theaters with more than one floor often will post workers to make sure that you belong on that floor. (If a 25 plex has theaters 20-25 on the 3rd floor, you will need to show a stub for one of those theaters to get on the 3rd floor). If your first movie was on the first floor and the next one you want to see is say, on the second, just whip out a stub from the last time you bought a ticket for the movie on the second floor. Put your thumb over the date and name of the old movie, and just let them see that you have an appropriate number.
I have not had any experiences with multiple story multiplexes so I can't say if this would work but if you make sure that you cover up the date and that the movie is still playing on that level things should be cool.

Credit card receipt Kit
With the new credit card machines in theaters, another way to sneak in without paying is possible. The machines print out a receipt that is the same size of a ticket, and perforated in the middle just like a ticket. Go to the flick with a friend, buy one ticket and put the credit card receipt underneath it. Hand them to the ticket taker at the same time. I doubt they will look at the underneath "ticket" because it feels exactly the same. Ask where the nearest bathroom is when you hand it to them, and that will distract them. This also works best when a lot of people are entering the theater.
The key here is the distraction. By taking the ushers mind off of what they are doing you increase the chance of this trick working. This one all really depends on how much the usher is paying attention but it would probably work most of the time, especially when it is busy. On the same note you can buy a child’s ticket and get in for half price (Trish)

Apply for a job Ian
Another great way to sneak in is to ask to apply for a job at the theater! You will always be taken to the manager's office, where you’ll be asked to fill out an application. The usher always walks away, and the manager doesn't pay you any attention, so after you apply, you are in the theater, free to sneak into the movies! This method works best if you're in high school, about the age of the average worker at a movie theater.
While this will get you in the theater it probably isn't a good idea. As a general rule of thumb you should wait till you have the job before you start stealing from your employer. Don't do this if you are serious about working at the theater, this practice is unprofessional to say the least.

Getting a refund Studman
If you ask for a refund within the first 15 or so minutes most theaters will refund your money, you can use this to see movies for free. You and a buddy go to see a movie and have him save your seat while you take both ticket stubs to get a refund. On the way there "befriend" the doorman so he or she will remember you, you might say that you have to set your car alarm or something like that. Go to the box office and get a refund. Visit your good buddy the doorman and slip back into your theater.
This tip was trimmed for clarity, if I messed up let me know studman. Anyway this is a pretty solid plan to see movies for free, you just have to be a people person and be friendly, other than that you shouldn't have a problem.