Assembling the "ship" and "crew"
Each turn consists of three rolls of the dice. The player must roll a 6, 5 and 4 in descending order.
The first roll of the dice shows a 6 a 4 two 3's and a 1. The player banks the 6 but must reroll the 4 because there is no 5 yet.
The second roll the player gets a 6 a 5 a 4 and a 1. The player banks the 5 and 4 and now they have a full "crew" for their "ship".
Getting the "cargo"
Once the "crew" has been assembled, the player may now stop and add the pips on the remaining 2 dice to determine their score from their "cargo" or the player may re-roll one or both of their remaining dice to try to get a higher number for their "cargo".
If the player chooses to stop with their 6 and 1 from the above example, they get a score of 7.
Determining the winner
The winner is the player at the end of a round who has the highest score.
To make it fun, you could add a consequence such as "at the end of the round everyone except for the winner must drink."