http://www.resurrectionacademy.org/t13-magicians-roll-rules#14

1- Press on "Post Reply" button

2. Scroll down a little and you will find the rolling section

3- Pick "Magicians"

4- Roll 3 and only 3, if you rolled less or more, your roll won't be counted. 

5- In case a message brought to you to tell you that there's a post before you, you will need to modify and adjust the values of your dice rolling.

6- after you post with rolling, Tytannial will show you what you rolled.