I pulled the topics from a specific category in my forum. Each topic has a reply_count, but it often seems to have no relationship to the user-experienced replies.
The reply_count parameter on a post gives you the number of direct replies to the post. A reply to a post is created by clicking the “Reply” button that is directly under the post. Replies to the topic’s original post are an exception to this. If a post is created by clicking the Reply button directly under the topic’s first post, it will not increment the OPs reply count.
The reply_count on a topic is the total number of direct replies to posts in that topic. It is not the total number of posts in the topic.