Medea plays on the weaknesses of those around her and uses flattery and self-deprecation to advance her plans. The first instance of Medea's cunning is in her manipulation of Creon. She plays upon the knowledge that Creon wants to be percieved as a kind and just ruler. She also plays on Creon's misogyny, knowing that though he is afraid of her, if she plays the role of the weak, helpless woman, he will be more easily bent to her will. Medea plays Creon's emotions, reminding him that as he is a parent, he should have some compassion for a mother trying to provide safety for her children. Creon is very clear about his terms of Medea's banishment, but through this manipulation, Creon grants Medea one day to remain. This one day is all of the time Medea needs to carry out her plan.
The next thing Medea has to do to carry out her revenge is to convince Jason that she is truly sorry for her anger against him. She plays on Jason's hubris, calling herself foolish for not seeing the excellence in his plan. Once Jason is convinced of Medea's penitence, he easily accepts the gifts she sends by her sons to Glauce. Of course, this allowance leads to the deaths of Glauce and her father and, ultimately, the deaths of the children.