Thrillers will create a sense of suspense, tension and uncertainty. They will do this by using different lighting, music, shot types etc… Within a thriller there are many conventions which have to be used as much as possible to make the thriller effect work properly.
Usually there is a crime in the narrative or story line of a thriller, it will keep the viewer captivated in the film and therefore preventing the film becoming boring as the criminal will be doing things which are something out of the ordinary, or they will be trying to escape society (cop chasing robber). Either way the criminal in the thriller does make the genre what it is, as most thrillers consist of one or have a similar substitute.
Thrillers are usually made up of a complex narrative structure, with false paths, clues and resolutions. This will have an effect of leaving a strong enigma by keeping the audience questioning the film and keeping their full attention by having them trying to solve the questions.
A narrative pattern of establishing enigmas which the viewer expects to be resolved. This will keep the audiences concentration as they will not be wanting to stop watching the film without finding out what happens individually. The audience almost goes into their own world whilst watching the film and tends to put themselves in the characters shoes.
A protagonist who is systematically dis-empowered. All thrillers have a protagonist against a antagonist at some point in the thriller both character will meet and there is where the action tends to kick in. for example fights, chases, arguments. The plot usually build towards a climax.
The thriller can be closely related to an action or horror film. It can be related with an action film because at some point the protagonist and antagonist will meet and have a distribution between adrenaline rushing actions. On the other hand it can be closely related to a horror as a horror builds tension ready to shock the audience in a highly similar way to what a thriller does.
Mis en scene which mirrors the protagonists plight. Mis en scene is exceptionally important in a thriller and needs to be used appropriately. For example if the character is upset put them in a depressive surrounding (lights, props, slow beat music and and scene). On the other hand if the character is over the moon put them in an environment which is joyful ( upbeat music, bright lights, cheerful scene, for example a park on a summers day, and happy props for example ice cream). Usually thrillers contain a lot of unhappy scenes so therefore the film makers use a lot of dark and dull lights in a dark and dull environment (sewers, tube station).
In conclusion many films with whatever genre have to have the certain conventions which differentiate them from one an other. This way you can label the film as to what genre it is. Collecting a lot of turnover profit once the film is released, as they can target their audience (comedy lovers, will pay to go and watch a comical film which stars a famous comical artist, Adam Sandler).