If you have a used copy from GameStop or eBay, check the spine of the DVD case. Many rental copies had the serial number whited out.
If you own a model and want to check its authenticity, look for the serial format: . The final two digits represent the production year (2011). The Adventures Of Tintin Secret Of The Unicorn Serial Number
The dusty air of Moulinsart Library smelled of old vellum and forgotten centuries. Tintin, his magnifying glass in hand, was not examining the grand tapestry or the carved oak beams. He was hunched over the model ship—the Unicorn —which sat on a felt cloth, its masts now splintered from the scuffle with the Bird Brothers. If you have a used copy from GameStop
: The key is typically printed on a sticker inside the physical game case, often on the back of the manual or beneath the disc tray. The final two digits represent the production year (2011)
The Adventures Of Tintin: The Secret Of The Unicorn Serial Number – A Complete Guide