Final answer:
The main objective of the game is to eliminate half the players. This process, comparable to a coin toss with a 50% chance for either outcome, ensures a fair and random selection of those who move on and those who are out.
Step-by-step explanation:
The objective of the described game where one must play 'rock paper scissors', and losers must finish their drinks and are eliminated, is primarily to eliminate half of the players. The reason for doing this could vary but given the context of half the playing field needing to be removed, the primary objective is to reduce the number of players, not necessarily to find the best 'rock paper scissors' player or purely for enjoyment, though having fun could be a secondary goal. This elimination process is similar to tossing a coin to decide who goes first in a competition, as it involves a 50/50 chance for each player, which makes it a fair way to determine winners and losers for that round. If you chose heads in a coin toss, you would have a 50% chance that the toss will go your way, indicating the randomness and fairness of such selection methods in games and competitions.