In each of the 3 films, there isn't necessarily only 1 main character, but a group and multiple killers. This is most likely to provide a range of personalities and likeable qualities for the audience. The use of groups also highlights the similarities and differences between the individuals, using the contrasts due to the often found juxtapositions within the groups to make the characters memorable, seem more like real people and emphasise important things about them, for example movement, thought, feeling, action and reaction, dialogue, expressions and personal styles.
In each film, the most innocent looking woman is the most brutal, again playing on opposites. The methods of brutality may differ from mind games to violence, but is present. It is also common for the killers to act on animal instinct, and to show no remorse. However, when the characters hide the evidence of their atrocities, the audience have the ability to detect fear in them, or decide that they were simply prepared and wise.
