Simple..majority rules.
Each round, you all vote, contestant with most votes is evicted.

Immunity, you each have one immunity pass, which you may use whenever.
You may only use it once. To use immunity, include the word IMMUNITY in your vote PM. Only first PMs count...you cannot change votes, or say IMMUNITY after voting.

Failure to vote = Elimination

In the event of a tie, a tiebreaker challenge will be set.