We've had a number of responses describing your thoughts on the problem:
Xing Yu from Catholic High School Singapore and Noor-Ul-Ain from Westfield Middle School both deduced that the later games will take more throws than the earlier games, because there are more rules and more restrictions. However, Xing Yu pointed out that this is only a general trend: "It could vary. If we get all ones for the first challenge, and get all sixes and fives for the other two, the second and third would take less throws." Edward from The Catholic School of St Gregory the Great, Freya from Simon Marks JPS and Precious from Bexley Grammar School all agreed that they thought the biggest factor was luck.
Maisie, Elle, Tahlia, Ryan and Finley from Moorgate CP School suggested that you could use your number bonds to 5 to work out what you need from the dice throws.
We'd like to hear if you have any more ideas!