When you act brave in an overly showy way, that's heroics. Sailing your little boat out into a raging storm just so you can brag about it later? Clearly nothing but heroics.
Heroics is used to mean both true heroism and a bravado that often involves dangerous or ridiculous actions. Use it in the first way for real bravery, like the heroics of a firefighter rescuing someone from a burning house or an emergency room doctor who saves a patient with a serious injury. Used in the second way, this word describes false or showy bravery and can even describe someone's speech: "He bragged about his success on the soccer field, but it was all just heroics."