Just had another couple of related ideas -

a) each player could at the start of the game have the option to either roll as normal - or roll "no 1s and no 6s" or roll "no 1s 2s 5s or 6s"

b) have certain handicapped games, where the reduces the max roll possible for people dependent on their scoreboard rating - so for games with 2 or 3 planes - the person who has the highest skill level is only able to roll 1-5, once you get up to 4+ planes start making best player(s) only able to roll 1-5 and lowest player(s) only able to roll 2-6


I quite like option a) not so sure about b)