Friendly fire

Friendly fire means accidentally shooting or hurting someone who is supposed to be on your side. Imagine you're playing a game of tag with your friends, and you're on a team with your best friend. If by mistake, you hit your friend when you're supposed to tag someone on the other team, that's friendly fire.

Sometimes in real life, soldiers who are fighting in a war may accidentally hurt or shoot one of their own team members. It happens because they may not be able to see very clearly in the middle of all the chaos, or they might mistake their own team member for an enemy.

Friendly fire is bad because it can harm or even kill the people on your own team, which makes it harder for everyone to work together and achieve the goal. Plus, it can make your enemies stronger because they won't have to deal with as many people fighting against them. That's why it's important to be very careful when you're working with others, especially when you're fighting in a war.