The TKTS booth is famous in New York & London, but Washington DC has something similar for half-price theater tickets in Washington.
Culture Capital DC has half price tickets to many theaters. You don’t have to wait until the day of the show. The biggest shows are not usually represented unless it is a very slow time (like mid-winter), but last New Year’s Eve, there were shows available at the Woolly Mammoth Theatre for the 11pm show! Other participating theaters often include: Studio Theater, Theater J, and Source.
The who-dun-it comedy “Shear Madness” at the Kennedy Center is often available and quite funny. It’s played over 10,000 times since 1987, so no wonder they have tix available.
Half-price tickets to plays at theatres in Maryland and Virginia, like Round House Theatre in Bethesda, Maryland, and Adventure Theatre in Glen Echo, Maryland, are often represented, as well as dance performances and occasional author and celebrity speaking engagements.