The Sunk Cost Fallacy
In this scene from the movie X-Men First Class, two superheroes are discussing how they should respond to a raid. Iceman thinks they should retreat, and Wolverine wants to stay and fight. But what is Wolverine's reason? Does he know something that Iceman doesn't know about their situation? Does he have some brilliant strategy that will improve their chances of success? His argument is that they need to fight because so many of their friends have already died. It's just an appeal to emotion and to the regret of their past losses, but Wolverine has not given any reason to believe that their fight would be successful. This is called a Sunk Cost fallacy because it appeals to something that is lost and can never be recovered.
This is the end of your intro to logical fallacies. Now you can continue onwards and learn how to play Sophistry, The Game Of Half-Truths.