ULTIMATE SCAM
If it was possible to give a zero star this restaurant certainly deserves it. When they advertise buy one roast duck and get second free, they present you with a "coupon" to redeem the free roast duck at your next visit. Let me just say, when i went to go redeem the coupon on the next visit i was told in order to use the coupon i have to pay tax on the regular value of the duck and 30% gratitude on the entire bill.
Overall, your "free" coupon is a scam. The tax part is arguable and debatable, but the "required" 30% gratitude on the entire bill to USE the coupon is quit pathetic.
Save your time and go somewhere else with better service and not a money grab.