One great tool in Moodle is the chat activity. The big difference between chats and forums is that chats are synchronous while forums are asynchronous. Meaning that chats are taking place live and all the learners are involved at the same time. Forums are independent of time. A forum discussion could take place over days, weeks, or months.
As always, on your course page, click on Turn editing on. Then in the section you would like it to appear, from the activities drop-down menu, choose Chat.
We're going to create a chat for a new topic on motion. The name of this chat room is going to be What would a world without friction be like? and, as you can see next, there are some guidelines added to the introduction. You can find the guidelines at the end of this section. This will be a one-off chat so choose No repeats, and to encourage thoughtfulness and politeness choose Yes to let everyone view past sessions. If you see your students face-to-face, it might be an idea to check...