Walmart specifically, as they are the only place where I've had to return something since 2003, has no such official policy, outside of software, electronics and the like. You will end up with store credit without a receipt, but you are not stuck with an exchange only and you certainly won't be denied. There is a reason that toy returns have been so abused lately, and that has led other stores to crack down. See Walmart's return policy here or read the billboard behind the Customer Service desk. Toys are not restricted to being unopened. Target will be more strict but if he grabs the receipt and returns it as defective, he'll be fine.