Dastardly deeds are acts of wickedness or villainy, often involving malicious intent. Sins, infamies, and evils are all terms used to describe such acts. Sins are considered to be transgressions against religious or moral law, while infamies are acts that bring shame or dishonor upon a person or group. Evils are acts that are morally wrong or harmful. All three terms can be used to describe dastardly deeds.