What are the rules and conventions of a thriller?

The first and one of the most important rules of making a thriller is to:

Grab the audiences attention. This could be done in multiple ways for one it could start of with an action scene. This could be a chase of some sort. This will leave the viewers wondering what is happening. Or it could start with a dramatic scene. For example someone's death and you would want to know the persons story and why this has happened to them.

Don't make the story line to obvious. You need to use a lot of techniques. These could include: Plot twists and red herrings. These techniques will insure that the viewer will not know the next point of the film.

Another rule that can be helpful in a thriller is if you point out the main characters strengths and weaknesses. This is because you then will understand what they are vulnerable too.

If you want to try and make a good impression on an audience you should really try to teach them a lesson. For example at the end of he film "The Birds". We had learnt the lesson that we take advantage of the birds and they do nothing in return. If they ere to flock together and take revenge we wouldn't have chance against them.

One more rule could be to keep secrets in the film. For example show hints of certain moments but do not tell the viewer of the full situation and reason. This will create more suspense and mystery.