Do I need to know how to play?
No. The rulebook is written to be read cold, and the adventure prints the words you say out loud. Running Brave and Bonkers means reading the marked text, asking what everybody is doing, and comparing a die roll to a number the adventure gives you. Nobody else at the table will know more than you do, and the kids will not test you on the rules.
What the job actually is
Being the Game Master comes down to three tasks. You say what is happening, you ask what everybody does, and you say what the dice mean.
The book does two of those for you. The words are printed and marked, so you are reading rather than inventing, and the number you compare a roll against is printed in the scene beside the thing they are rolling at. What is left is asking what do you do, then listening to five kids answer at once.
How much prep before Saturday
Fifteen minutes, and ten of those go on reading the boxed text to yourself so you do not stumble over a name the first time you say it aloud. Skim the setup page, keep the module open beside you, and start.
The monsters are printed in the scene where you meet them, so nothing sends you back to the rulebook mid-fight.
When you do not know a rule
You say “roll and let us find out”, and that answer is always allowed. Everything a kid needs is on their hero sheet, and the How to Play page prints on the back of it, so most of what they ask gets answered without going through you at all.
Kids do not audit you. What they notice is hesitation, so decide out loud and quickly, and if it turns out you had the rule wrong, say so at the next fight and carry on.
When they do something you did not plan for
They will, usually inside the first twenty minutes. Somebody at your table will push a goblin off the bridge, which the module expects: the river under it is warm, slow and shallow enough to stand up in.
Say yes, ask for a roll, and carry on. The module marks which parts of a scene can be dropped and which can be drawn out, so a detour still fits inside the hour you had.
Do you have to read the rulebook first
No. Read the adventure. The rulebook is there for the second session, when somebody wants to know what happens if they climb the thing instead of talking to it.
It also helps to know that nobody else at the table has played either. The kids are not comparing you to a Game Master they had last year.
What you never have to do
- Build a character. Seven heroes come finished, one page each.
- Write stat blocks. Thirteen monsters come with everything needed to run them, and six ready-made fights.
- Do encounter math. The first fight is built so the party cannot lose it.
- Track initiative. You are the turn order, going round the table by seat.
- Plan a campaign. One adventure is a whole story with a real ending.
Run it tonight walks through the first hour beat by beat, for anybody who wants to see the shape of an evening before committing one.