Rule 1.406 Reply

Here's a plain English summary:

If someone files an answer in a lawsuit, the other side doesn't automatically get to respond to it. But the court has the power to order a written reply if it thinks one is needed. This also applies to answers made in response to a cross-petition (a claim one party makes against another party in the same case).

In short, replies aren't required as a normal part of the process. They only happen when a judge specifically asks for one.