Motte-and-bailey fallacy

Imagine you have a castle with a big wall around it. The castle is called the "bailey" and it's where you live safely inside the walls with your family and friends. But sometimes bad guys try to attack your castle! So you run back to the "motte," which is a little hill inside the bailey where you can see everything around you and defend yourself.

Now, the motte-and-bailey fallacy is when somebody tries to argue in two different ways about the same thing. It's like having two different castles: one is the "motte" and it's very strong and clear, but the other is the "bailey" and it's not as strong or clear. When the bad guys attack, you quickly run to the motte and defend yourself there. This is like arguing your strongest, most clear point.

However, when the bad guys go away, you then go back to the bailey. This is like changing your argument to something that is not as strong or clear. You might do this because somebody has argued against your strong point, and now you want to argue something that is easier to defend.

But this is not fair! You can't keep changing your argument depending on what somebody else says. It's important to stick to your strong point and defend it with evidence and clear reasoning. So, just like how you wouldn't keep changing your castle to avoid an attack, you shouldn't keep changing your argument to avoid being proven wrong.