There is a great deal of manipulation occuring throughout the entire play of The Crucible. In the first scene, Reverend Parris is trying to figure out what is wrong with Betty. The Putnams arrive, and immediately jump to witchcraft as the result, and suggest that the culprits are various people they have grudges against, such a Sarah Good and Sarah Osburn. This is the first occurence of manipulation. They see an opportunity to make the situation go in their favor, and they jump on this opportunity.
Abigail is the most manipulative person in the play. When she is caught dancing in the woods, she sees the opportunity to accuse people of witchcraft to avoid getting "whipped" for "dancing." Knowing full well that the accusations could lead to the deaths of those accused, she stays adamant that various women are witches and are inflicting on her whatever spells or curses she can conjure.
Not only does Abigail sees the accusations as a way to avoid punishment, but she also sees it as a way to get back at John Proctor and Elizabeth Proctor. Because she had an affair with Proctor, she obviously has a grudge against his wife and accuses her of witchcraft. She is able to manipulate the situation by making it seem like Elizabeth is inflicting harm on her by magic and witchcraft.