Reselling theme park tickets is generally prohibited by the major parks, including Disney, Universal, and SeaWorld, and can often be illegal depending on local state laws (such as Florida’s "anti-scalping" statutes). Most modern theme park tickets are non-transferable once they have been used for the first day of admission. Parks like Walt Disney World use biometric finger scanners or photo recognition technology to link a specific ticket to a specific individual. If you attempt to use a "partially used" ticket purchased from a third party, it will likely be flagged at the gate, and you will be denied entry without a refund. Even for unused tickets, most parks state in their terms and conditions that the "sale or transfer is void" if done through an unauthorized vendor. There are legitimate authorized resellers (like undercover tourist or AAA), but buying from an individual on platforms like eBay or Craigslist is extremely risky. You may end up with a counterfeit ticket, a voided ticket, or an expired one. It is always safest to purchase directly from the park or a verified travel partner to ensure your admission is valid and supported by the park's guest services.