So you want to be scary?
Sounds kinda silly, doesn't it? Doesn't everybody know how to be scary? Well... in a word: No.
How many times have you been to one of these walk-thru haunted houses, only to be repeatedly startled or chased... but never truly scared?
The first thing you need to understand is that there is a difference between scaring someone and startling someone. It is easy to startle someone... just jump out and go, "Boo!" or make a sudden loud noise.
A good haunted house is like a good recipe. You have a carefully balanced mixture of ingredients. Chases and "in-your-face" appearances can all be useful and fun parts of the experience, but a haunted house with no suspense or chills is about as much fun as a bowl of salt.
When a person is startled, they react without thinking. They will probably yell or scream, and perhaps bolt for a door. They may even punch you, but that is just the "fight or flight" adrenaline reaction.
But to really scare someone, you have to give them time to think. A person gets scared when they have time to think about their situation. Your victim's own imagination is your best ally, and all you have to do is give it some material to work with and a chance to take over.
In the better haunted houses, the actors and directors know how to give you a chill they can build suspense on, and induce a sense of dread. They know how to let the victim's mind produce worse monsters than makeup and lighting alone could manage.
Being scary is so much more than "jump out and go Boo."

Stillness
In this world where everybody and everything always seems to be in motion, perfect stillness draws the eye. Take a moment to look around you when you are in a place with other people. Notice how many of them are in subtle, or not-so-subtle motion. They walk, they fidget, they talk... they are always in unconscious motion.
Practice being extremely still. Learn to breath shallowly, and make your movements as small and as smooth as possible. Learn to see with your whole eye, using your peripheral vision so you can observe the world without it knowing it is being observed. When you have achieved some measure of control, try this experiment (with friends nearby to help you out if things go badly.)
Find a public place, like a diner or a park, and stand in a visible place. Become very, very still. Make your breathing shallow, concentrate on quelling all those unconscious moves. With an unthreatening expression on your face, pick a direction and gaze steadily at nothing, blinking slowly when you have to, and open your awareness of your peripheral vision. After a while, you will begin to notice people looking at you curiously. For some, you will become the topic of conversation. A good Samaritan may even ask you if you are all right. (How you respond is up to you.)
The contrast of someone standing perfectly still draws the attention of others. At first they will be uncomfortable looking at you, and will look away and try not to stare. After a while they may become bolder in their reactions, perhaps even trying to get a rise out of you. Your behavior is alien, and they will begin to try and categorize you. Are you real? Are you sick or on drugs? Is that really a person?
In most haunted houses, you can count on someone rushing at you. In fact, on a subconscious level, we are well equipped to deal with someone rushing at us... our brains are programmed to either run or fight. Screaming, of course, is optional. But because we are "wired" to deal with this form of threat, it holds no lasting impression for your victim. Once the threat abates, they can easily forget about it and move on to the next scene. On the other hand, you can be sure that the people in the diner or the park will be talking about you and the odd behavior they saw for a lot longer than if a madman had gone screaming by. They can understand and explain a madman...
Stillness is unnatural. The unnatural is hard for our minds to pigeonhole and deal with. Since people can't categorize your behavior, their own imagination will take over trying to put a reason to it. A person's imagination holds more "chill potential" than almost anything else you can name. Unnatural stillness causes the victim to dwell on your behavior, and the tension builds. You can use this tension to amplify the effect of subsequent ghouls and scares they encounter. You can use this tension to ensure that your victims remember you with chills, long after they leave the haunted house.
But like a recipe, this one ingredient is best when mixed in with others. Combined with Stares and the right kind of Movement, Stillness is a powerful amplifier of fear.

It's Alive!
This is a great effect if you have a lot of self-control. The basic idea is to use body language to convince your victims that you are simply a dummy with a mask and loose costume. At the right moment, you move just ever so slightly.
We used this technique with great effect on the people waiting in line in the lobby. The victims have time to get used to your presence and usually discuss whether you are real or not. If you are really good at this, you can convince them quickly.
One way to look "fake" is to lean stiffly against a wall, as if someone propped a dummy there. This artificial pose usually is enough to convince most of your victims that you are inanimate. Your costume should include some sort of face covering such as a veil or some makeup to make you look less real.
As you watch them discuss you, decide on your victim. Pick the one who shows the most doubt in their eyes. Then, when the others are not looking and only your victim is watching you, turn your head just a tiny bit to look at them. Make sure that only your victim sees you do it.
This usually causes your victim to do a little jump and perhaps a squeak, and you then watch as he or she tries to convince their companions that they saw you move. If you can repeat this several times before they enter, you will have at least one of the party totally primed and ready to jump at shadows... which will in turn spook the others.
Another trick is to wait until they have convinced themselves that you are fake. Wait for them to turn away for a moment. You quietly step closer towards the group and resume absolute stillness. As your victims turn back towards you, it will seem as if you materialized next to them and they may jump out of their collective skins.
Another way to take advantage of this technique is to have a co-conspirator across the room cause a distraction for a moment. When all eyes are off you, you slip out a nearby exit. Then peek and watch the consternation as the whole party who convinced themselves you were fake start to have serious doubts. They will spend the rest of the trip through the haunted house expecting you to reappear just as suddenly. This is great priming for the victims before they actually enter the Haunted House.

Stares
The next time you are in a public place, take notice of how many people are actually looking into the eyes of other people. Even if they are talking to someone, chances are they are looking away, here and there, and at most, merely glancing at their companion's eyes. In our culture, looking into someone's eyes for longer than a few moments means one of two things: intimacy or challenge.
In a haunted house, good eye contact is more effective than a loud scream. Facial expression is important, because it telegraphs the intent of your stare, so it is best to keep your face perfectly neutral and let them draw their own conclusions.
Often the victim will have trouble maintaining eye contact with you, yet they will also find it hard to look away. Much like a snake hypnotizing a bird, a victim will feel physically trapped by your gaze, and this only amplifies their feelings of helplessness.
There is something of a gender difference in reactions to this. A man staring at a woman is more likely to be considered threatening than if a woman is staring at a man. In fact, the woman staring at a man may find the man interprets this to be an invitation. On the other hand, a man staring into the eyes of another man is much more likely to cause a challenge response.
But like a recipe, this one ingredient is best when mixed in with others. Combined with Stillness and the right kind of Movement, Staring is a powerful amplifier of fear.

The Evil Eye
This technique will freak people out even if they are nowhere near a haunted house. But be aware that for some people, it could cause aggressive action... against you!
There are a couple of variations. You will probably recognize this first one from any number of Hollywood movies. But you don't have to be Hollywood to use it well.
This works best if the person does not know you. As you stare straight ahead, slowly turn your head and look at them. Do not change the expression on your face. Do not answer them if they talk to you. If you decide to look away, again slowly turn your head back to the forward position. In all cases, keep your eyes staring straight out from your head as if you can't move your eyes. The key to this is doing it slowly and deliberately.
Human animals do not like to be stared at, much the same way dogs get upset if you stare them in the eye. Something in our basic makeup suggests that someone looking at us oddly is a threat. The slow turning of the head adds to this sense of creepiness and suggests that you are in full control, while at the same time suggesting madness.
A similar technique is also a good one to use in the Haunted House lobby line. If you find several victims standing in front of you waiting to get in, pick a specific victim and keep a steady unblinking gaze on them. Ignore everything they say. Remain silent. Watch, as they are fascinated and repelled. They will not be able to stop checking to see if you are still staring. They will probably get somewhat hostile and uppity, but deep down, this really unsettles them. All the brave talk just means you have succeeded in getting to them.
You can capitalize on this when they all turn away for a moment. Silently take a big stride towards them and stop perfectly still, staring all the while. When they next turn back to see if you are still there, they will most likely jump and scatter, because to them it will seem as if you simply materialized closer to them.

Movement
Lunging and chases have their place, but they can be overused. Sudden movement and obvious aggressive actions produce more of a startle effect or a defensive reaction. While these can be amusing, they are not as effective as true fear and dread. Keeping the concept of "otherness" in mind, make your movements different from what your victims might expect. Our deep-seated fear of things unknown and alien is a rich area from which to produce chills.
The extremes are the most productive. Either move so fast (or appear to) that they almost can't see you, or move so slowly and deliberately that they can't take their eyes off you. Isolate your gestures instead of moving your whole body. A small movement of your head, in an otherwise still pose, can be much more dramatic than a lunge. A slow curling of the fingers in a "come hither" gesture can be much more effective than a grab. Moving just your eyes in answer to a question can communicate more than words. Simple, deliberate motions, well timed, can push those fear and dread buttons in your victims' heads.

Alien Motion
When you are very still, or when you move slowly, people will find it hard to look away from you. For example, as a group of victims approaches you, after a period of stillness, slowly turn your head to face them. In the proper environment, this will produce chills and fear reactions that are much deeper than a mere startle reflex. In addition, while they are preoccupied with you, a fellow ghoul can quietly appear behind them, make a small sound, and wait for the resulting screams as those in the back of the group realize they are not alone. The resulting domino effect is much more powerful because you have built up suspense and primed them for a release.
At the other extreme, a quick "here and gone" can also put your victims on edge. Pop your head out from an unexpected place, and before they can quite figure out what they have just seen, disappear again. Do this several times from different, unexpected locations, and you will have them trying to look everywhere at once. Combine this with some of the other techniques discussed, and you can truly make their heads spin.
Another technique related to "here and gone" is the disappearing act. Allow your victims to see you and approach. Arrange for a distraction that makes them turn their heads away from you for just a moment. In that moment, duck into a preplanned hidden-hole before they turn around. When they turn back around, your sudden disappearance will be just as distressing as a sudden appearance. You can milk this further by arranging a series of hidden passages throughout the haunted house that will allow you to get ahead of them several times. After the third time, instead of disappearing, have another ghoul join you, and slowly advance on them. The result will have much more impact because of the priming you did.

Perspective
Another way to push people's psychological buttons is to appear either below or above their normal line of sight. In a haunted house environment, one way to implement this is by putting yourself on a shelf that is slightly above head-height of your victims. Securing yourself with bungee cords or a counterweight system can allow you to loom over them in a very unnatural way. If you set the scene properly, they won't see you until you are practically on top of them, and your mere presence is usually enough to make them cower back into their companions or duck and run. The most entertaining victims will go directly from standing to sitting in one quick drop.
On the other hand, if you put your victims on a raised ramp or walkway, and you put yourself off to the side, on the floor below their normal line of sight, you can freak them out quite easily. Small motions, faint sounds, rapping the floor beneath them, or grasping motions towards their feet will usually have them stepping high and squealing.
Have you ever seen people on TV running around, jumping on chairs and trying to get off the floor when they see a loose mouse? You can trigger this reaction on the same level as your victims if you remain low to the ground in a squat, and scuttle towards them in an unnatural fashion. There is something in our brains that screams "that ain't natural!" and causes a flight reaction.

Vocalizations
Screams and other loud noises may cause a startle reaction, but after a while, your victims become somewhat immune to this. The reaction and adrenaline rush is short-lived and won't make much of a lasting impression. A well placed screech or howl may be a good spice to add to a scene, but it can be made much more effective if the victims are "primed" first. You prime them by working on their subconscious.
Your character's sounds are very important. Some characters do not talk at all, others talk in a high, rustling whisper or low gravelly rumbles. Save the screaming and yelling for climactic moments, and use soft, subtle sounds to draw your victims in closer. A quiet growl in a darkened hallway is much more chilling than a loud screech.
For example, Scuttles doesn't speak at all, but he does make a noise... a strange, hard to identify noise. Scuttles' sound has been described in various ways by different people. Some think it sounds like a scythe cutting through grass, others say it sounds like some oversized insect. But all agree that hearing this subtle, clicking, skittering, disassociated sound in a darkened room gives them chills.
Spend some time with a tape recorder and your imagination. Work on developing a "voice" for your character that has a flavor of the unnatural to it. Practice it and make sure you can do it for long periods of time if you are doing a haunted house. (You can get some interesting sound effects by experimenting with sucking your teeth and clicking your tongue.) Once you think you have a good one, try it out on some friends who understand what you are trying to do. It may look and sound silly in daylight, but things take on a more sinister aspect in the dark.
Sounds can reach into the victim's mind and trigger all kinds of fear and dread buttons. Subtle, hard to identify sounds are best for making the victim's imagination work for you. (Remember, the scariest things are in your head.)
Volume is not the issue... it just has to be loud enough for them to hear it above the rest of the local noise, and even then, you will hear them drop to a whisper in order to hear it better.
If you slowly build your victim's terror by gradually increasing their fear, a well timed cacophony of screams as they leave the haunted house will send them running and remembering you for a long time. so trite and obvious.)