I think in your profile there should be a switch . It is called the war switch. If it is on, people will be in wars. If off, they won't be in any wars. You can switch the button whenever you want. This way we can make the rule saying that people that are in wars can't leave the clan. If we didn't have the war button it would be unfair because people could be brought into clan wars without wanting to. If the button is on you know that you need to stay the whole war. I can't tell you how annoying it is when people leave during preperation day or before they attack. That is why the war button on you screen (maybe by the corner were it displays the gold and elixer amounts) will be helpful to clans that want to win clan wars. Thanks for reading.