In a perfect world, every DM would have ample time and resources to plan out the perfect adventures in for their party. However, that is not always the case, and sometimes game night might sneak up on a dungeon master, or they could be called to action at short notice.
No matter how experienced the DM might be, having some quick and easy one shot adventures on hand can be a powerful secret weapon to creating a fun, low-stress experience for everyone at the table.
There are many resources available for DMs who want to dive deep and homebrew their own games or run long, complicated campaigns.
Thankfully, there are also many short adventures that can either be slotted into an ongoing campaign or run as a separate standalone game, with little preparation required by the DM.
These can come from a variety of sources, including the official, several official books, or adventures from websites such as DMs Guild.