Weird rules the Queen's Guard have to follow

People flock from all over the world for a chance to see members of the Queen's Guard standing silently at their posts in their giant fluffy hats and red coats.

But other than pictures of people trying to break their stern demeanour or the occasional video of a guard putting a particularly annoying tourist in their place, we don't see much of them.

However there are very specific reasons behind their unsmiling faces and tall, "Bearskin" hats — in fact their whole uniform is designed with potentially terrifying and embarrassing events in mind.

Queen's Guard pushes a tourist at Windsor Castle. Photo / Youtube

And while you think it might be funny to try and make a guard crack a smile, you could be costing them more than you realise.

So here is a list of some things you probably didn't know (or might have wrongly assumed) about the Queen's Guard.

DON'T ASSUME THEY WON'T REACT IF YOU ANNOY THEM

While they might come across as unshakeable, they are humans and, just like anyone else, some of them have more patience than others.

It is not unheard of for a guard to shout warnings at unrelenting tourists or push them aside if they are in their way.

Short commands like "Make way for the Queen's Guard!" are permitted if the situation calls for it.

A bead of sweat falls from a member of The Queen's Guard as he takes part in the Changing the Guard ceremony at Wellington Barracks, in London. Photo / AP

Recent footage of a Queen's Guard shoving a tourist out of the way outside Windsor Castle shows that you really don't want to be in their line of sight when their patience wears thin.

If someone is being particularly aggressive or they are perceived as a threat the guards will point their rifles at them as a warning.

THOSE GUNS ARE PROBABLY NOT LOADED

During a Q&A on Reddit, a working guardsman, under the username "nibs123", revealed that most of the time the guns they carry aren't actually loaded.

He said that the majority of the time police will take care of any tourists that might be taking things too far.

However this changes if there is a perceived threat in the area.

"You only carry live rounds if there is a high threat level that someone will attack," he said.

A member of The Queen's Guard's, from the Royal Canadian Air Force (RCAF) takes her position to begin guard duty. Photo / AP

"But I have never carried any."

But even if it isn't loaded, having a sharpened bayonet pointed at your face wouldn't be a very pleasant experience.

MONEY IS ON THE LINE IF THEY SMILE

People will do almost anything to get the notoriously stern-faced guards to crack a smile, but what they don't realise is that doing so could cost them big time.

If a Queen's Guard is caught by a superior smiling or laughing at a tourist's joke or silly antics it could cost them.

Guards performing drill near Buckingham Palace. Photo / Getty Images

The guardsman said they can be charged "a few days to a week's pay" if they are caught.

According to the Reddit thread, it is usually around ₤200 ($A355) if you are seen laughing or smiling.

THEY HAVE TO FAINT A CERTAIN WAY

Standing outside in the sun for hours on end dressed in a fur hat and layers of thick clothing is not an easy task and even some of the most disciplined guards succumb to the heat.

But even when fainting, there is still protocol that has to be followed.

If a guard starts to feel a bit light-headed while on duty they are trained to "faint to attention" meaning they have to keep their disciplined pose even when falling to the ground.

A Guardsman faints with heatstroke during the Trooping of Colours ceremony, held in a heatwave. Photo / Getty Images

This is why you often see pictures of passed out guards lying flat on their face.

THE CREEPY REASON FOR THE HATS

Called Bearskin hats, they were originally designed to make the guards seem taller and more intimidating.

In the case of an attack, soldiers would aim for their heads, so they would fasten their chin straps under their noses to avoid the hat "breaking our necks" when it got shot off, the guard said.

THE EMBARRASSING REASON THEIR PANTS ARE BLACK

When a member of the Queen's Guard is on duty, there are very few circumstances under which he would be able to leave his post — and using the bathroom is not one of them.

The Reddit user recalled one scenario when he was in a parade in front of a large crowd when one of this fellow guardsmen needed to "relieve himself".

"(He) couldn't hold it any longer. He was on the front row and left a huge obvious puddle where he was and some of the crowd noticed and started laughing."

The dark colour and thick woollen material of their pants are an attempt to make it less obvious if an accident should occur.