Oh dear, I do believe your pants are on fire

There is definitely a lot of lying going on in the play Much Ado About Nothing. For example when all of the characters are at the party and Claudio tells Don John that he is Benedick (2.1.133). Don John told him that his brother, the Prince, was in love with Hero and that Hero shouldn't marry the Prince because she is not worthy of him (2.1.134-136). By lying to Don John Claudio heard something that he wish he did not hear. He didn't really have any reason to tell Don John that he was Benedick, so it's not morally or ethically justified, but then again by claiming to be Benedick he didn't do any harm except to himself. On the other hand when Don John lied about his brother being in love with Hero he was hurting others. He knew this to be false and that this lie had the potential to make many people upset and confused, especially Claudio. This lie was definitely unmoral considering he only said it to create chaos for everyone around him.
However there is also some lying that occurs to benefit others. For instance when Leonato, Don Pedro and Claudio lie about Beatrice being in love with Benedick while Benedick is in ear shot. (2.3.81-83). They have good intentions and are trying to arrange a situation to set up Benedick and Beatrice without either of them knowing it. By learning that Beatrice is in love with him Benedick suddenly becomes aware of how beautiful she is and her amazing wit, deciding that he loves her back. This reaction was exactly what they wanted and expected, creating a more peaceful environment for all. While this lie does have some morals and ethics behind it I still don't think they should have put it into action. While it was all fun and games and turned out the way that they had hoped messing with people and making them believe that someone is in love with them is not a very nice thing to do.