We've all been there. You're walking down the street when you hear a scream, and you see a gang of black clad men jump in a van before driving away from a burning building with the tires squealing. You run up to help, and the trapped Olympic women's volleyball team inside screams that all the doors are locked and they can't get out. Do you dig into your pocket, break out your phone and heroically call 911? Or do you kick in the door and save the day?

You'll probably try to do the latter, but if you don't know what you're doing you might have to call 911 with a bruised heel and a broken ankle. That's why it's important to be prepared, and this simple guide should help you when the time comes.

And for more guides to random acts of badassery, feel free to check the rest of my LifeHack contributions, as well as my Vocal archive!

Step One: Know Thy Enemy

Oak... we meet again.

Any experienced door-fighter knows that different models have different strengths and weaknesses; that's why you need to take a close look at what you're kicking in before moving forward. First, look to see which way the door swings. Doors that swing away from you are going to be the easiest to kick in, while those that swing toward you will be almost impossible unless they're cheap, flimsy, and you've been doing your squats religiously.

It's also important to take a look at the frame and at what kind of lock a door has. If there's no deadbolt then all you have to do is kick next to the latch hard enough to break it open. If there is a deadbolt, though, then you have to kick it hard enough to snap the deadbolt through the door frame. If the frame is cheap pine, this is going to be simple, but if it's hardwood and concrete, then this might take a while.

All of that said, the goal is to plant your kicks just above, below, or next to the latch. That's where the door's anchored, and it's the spot you need to smash in order to bust open the recalcitrant portal.

Step Two: Put All Your Force Into It

Let the expert show you how it's done.

It's not enough to know where to kick; you also have to know how in order to really get the job done. As such, you should face the door squarely, roughly 2-3 steps back from it. Take a step to build up momentum, and pivot as you kick. Plant your non-dominant leg and drive your dominant heel into the door just next to the latch, just above it, or just below it.

This kick can take the form of a side-kick (where the foot is horizontal to the ground), an "overhand" kick (where the foot is perpendicular to the ground, and the kicker drives the heel straight forward; the style most commonly seen on TV cop shows), or a mule kick (where the kicker faces away from the door and drives his or her weight backward into the door, similar to how an angry quadruped would break your ribs). Different methods work for different people, but you need to find the kick that delivers the most power, and you need to put your entire body into the blow. Don't just kick with your leg; drive yourself into the door, focusing all your weight and force onto your heel.

It still might take two or three kicks, so if you don't knock the door down on your first try, make sure you hit it again quickly. Time is often of the essence. Lastly, do not throw your shoulder into the door under any circumstances. If you're not an NFL lineman, you won't get enough force into the blow, and you might dislocate your shoulder in the process.

Step Three: Always Use Proper Equipment

You know, if it's available.

Kicking down a door, while cool and manly, also has a pretty good chance of injuring the kicker. If you don't know what you're doing, then the chances of getting hurt shoot way, way up. Ideally you're going to want a pair of sturdy boots that will add some weight and authority to your kick, but if all you have is a pair of tennis shoes make sure they're laced tightly, and that you have as much support as you can get. Broken ankles, strained tendons, and torn muscles are all possible when you fight the door, and the door wins.

In an ideal situation, though, you'd have something other than a boot-shaped key to bust down a door. That's why the SWAT team carries a battering ram, a nine-pound sledge, or a fire ax; because if you're not a martial arts master or a kung-fu Clydesdale, smashing down a door is an iffy proposition.

Additionally, police and military tend to stand to either side of a door when they start kicking. Why? Because if you're directly in front of a door and you don't knock it in off its hinges people are going to start shooting. It's best to be out of the line of fire when that starts.

Lastly it's important to remember that even if you give it your all and hit that sweet spot with everything you've got, a door wedge is going to stop you cold. Even if you bust the lock, smash the latch, and splinter the door frame, a security wedge can use simple friction to hold that door closed for a dozen kicks or more. When that happens, it's best to bust out a window and call it a day.