The general reasons I see are stuff like 'somebody slips on the driveway of your house and sues you for a ton of money' or 'your tree falls and crushes somebody else's house' or 'you hit somebody in a car accident'. I don't think I'd be doing anything unusual to cause them, but accidents happen to people, and some of the people they happen to either can't admit that they do, or like to see them as a way to profit. If you have assets like houses, they can think that they're likely to profit off of suing you over the accident. I guess my rule on things is 'insure against things you can't handle if they happen', so I insure my house against fire, but have a high deductible, because I can deal with minor damage fine, but not loss of the entire house.