Well, for one, security is a top priority at New World Stages. They want to make sure everyone has a safe and enjoyable experience, and that includes checking what's in your bag. It's kind of like going through airport security, but way less stressful, and you don't have to take off your shoes.
So, what can you bring into the theater? The good news is that you can bring a small bag, like a purse or a backpack, as long as it's not too big. Think of it like a carry-on bag on a plane - if it fits under the seat in front of you, it's probably okay. But, if you're carrying a giant duffel bag, you might be out of luck.