Let me start by saying that this subject often raises a few eyebrows because by it's very nature it can seem a futile exercise...... until you have your first lucid dream. Then it all becomes clear.
Reality checks are exactly what their title describes. They are a method by which you can check to see if what you perceive as being real IS real.
At this point, most people will say "I know my reality is real!" - but do you?
Sight, hearing, touch, smell and taste are the five main ways that we perceive our reality. Some would argue that there are six ways, but that is a whole other story.
Now, all of those senses go into the brain to be interpreted as 'Reality'. What happens when the brain starts to make its OWN reality? i.e. when you are dreaming. How as a lucid dreamer can you tell if things are real or not? You need some method that will differentiate the real world from the dreaming world.
The answer is the reality check
The reality check is THE most powerful method for having a lucid dream.
Very few people know this but you will often have what is know as a 'false awakening' during the night. Those are the times when you wake up and do something such as checking your clock or maybe listening to a noise that may have disturbed you.
Often, you haven't woken up at all! What has happened is that you have become conscious IN your dream. Yes that's correct, you have been lucid dreaming and you never knew it.
If you had been used to reality checking, you would have been able to spot this and would have had a wonderful lucid dream.
As you can see, checking your reality can bring the awareness needed to trigger a lucid dream, whilst you are dreaming. This opens up opportunity's to lucid dream that you never knew were there.
There are several different methods which enable you to distinguish between this 'real' world and the (much more fun) lucid world.
A simple method that I prefer to use is the 'pinch nose' relaity check. This one can be done anywhere anytime without looking silly. Simply pinch your nose with your mouth closed and try to breath in through your nose.
If you cannot breath in, you are awake in this world. If you can breathe in then you are in a dream. For reasons unknown, you can breath through a closed nose or mouth in dream world. This will cause you to become lucid and hey presto, you are having a lucid dream!
It is possible to lucid dream without using reality checks but I would say that approximately eighty percent of my lucid dreams are triggered by reality checks.
