This is an entry in our Disneyland 101 Glossary: Disneyland Resort definitions in under 101 words, from Mouse Brief.
You may hear other guests use the phrase “hard ticket” to refer to events at Disneyland Resort which are not included in general admission and require a date and event-specific ticket. These events typically occur after regular park hours. Oogie Boogie Bash—A Disney Halloween Party and the Disneyland After Dark series are two examples. Guests wishing to attend these events will need to purchase an event-specific ticket even if they have valid general park admission for the same day. The name does not derive from the tickets being “hard to get,” but, coincidentally, they often do sell-out quickly.