Can I get down to the designated breakfast floor without a hotel card?

Generally speaking, a five-star hotel can have breakfast with a room card, but it depends on the specific situation. If the front desk gives you a breakfast coupon when you check in, you can use it to eat. If you don't give breakfast vouchers, you can eat with your room card. Of course, your room rate should include breakfast. If the room rate does not include breakfast, you can't have breakfast with your room card, so it depends on the specific situation!