Here are the updated product key and serial number for AutoCAD 2018:

If you're looking for other versions of AutoCAD 2018, here are some additional product keys and serial numbers:

A: This means the serial number is a leaked, public key that has been used too many times. You cannot reset it.

There is a persistent legend in the CAD community about a "Regcode" Easter egg found in older versions. While modern security has scrubbed the whimsical Easter eggs from the main interface (mostly due to corporate liability), the structure of the validation remains a tribute to the earliest days. The verification algorithm still checks for a specific hexadecimal signature that mimics the handshake of those original hardware dongles from 30 years ago.