Help! from out of town are coming to visit for the weekend and they want to see a Broadway show. How can we score cheap tickets at the last minute?
There are basically two ways to get cheap tickets.
First, we all know about the TKTS booths. There's one in Times Square and one in South Street Seaport. Depending on what time of day you want to see a show, you go stand in line at a designated time. This can be an excellent way to get tickets for half price, but you likely won't be able to get tickets to a show with otherwise great ticket sales (The Producers, for instance, is a near impossibility, but you can probably get tickets to the revival of Fiddler on the Roof.)
The other way to do it is to get rush tickets. The way this works is you show up at the theater at a designated time (different shows have different policies) and either wait in line or put your name in a raffle. Tickets typically cost $20-$25 and will be in the front two rows of the theater. (This was sort of disadvantageous when we saw 42nd Street because we couldn't see anyone's feet and the show is basically two hours of tap-dancing.)
Both options can be hit-or-miss. We've scored rush tickets, but also not gotten our names drawn for the lottery and had to pay full price. The lines at the TKTS booths can go on for blocks, so be prepared to wait and not even be guaranteed to get tickets to the shows you want. If there is a particular show you want to see, call the box office; they might even be willing to tell you which nights are easier to get tickets on.
If you've got more time and love theater as much as we do, you can sign up for mailing lists (such as Playbill's that will send you discounts over email, or join the Theater Development Fund (which, alas, has some eligibility restrictions).