Any alliance with the numbers to do so can hypothetically split votes successfully counter the threat of a Hidden Immunity Idol; however, the strategy is not used unless there is a reason to suspect one of the targets has an idol.
The split vote is often considered a risky strategy, because it makes it easier for a supposed alliance member to renege from the alliance and vote out a loyal member. If there are an unequal number of people voting for each side of the split, care must be taken to lessen the impact of a single "flip" against the alliance.
If the majority has at least twice the minority's numbers, they can split the votes between two targets without risk of having one of their own members idoled out.
If the majority has at least two more than twice the minority's numbers, they have an option as to whether to split evenly between the targets to reduce the risk of a flipper or surprise Extra Vote, or split unevenly to prevent the minority alliance's votes from influencing which of the two targets is voted out.
The primary target of a split vote may still be able to survive the Tribal Council, resulting in the secondary target (or a third person) being voted out:
- Using a Hidden Immunity Idol, negating all votes against them. (First attempted in "It's a Turtle?!", but the majority voted for someone else. First succeeded in "Not the Only Actor on This Island".)
- Voting against the secondary target. This can only succeed if the splitting alliance has an equal number of people voting for each target. (First attempted in "Blackmail or Betrayal", successfully)
- In seasons where the Extra Vote advantage is in play, it can be used to counter an attempted split vote. (Never attempted.)
Minority Split Vote
A minority split vote is when the minority at a vote decides to split their vote between two targets, knowing that an idol could be played by the majority alliance in response to their idol play that will create a null vote wherein the majority would still have control at the vote restart.
The first time the minority alliance intentionally split the votes for this reason was in David vs. Goliath, when Davie Rickenbacker played his idol on Christian Hubicki, and in response, Dan Rengering played his idol on Angelina Keeley. However, the minority David Alliance had split their votes between Angelina and John Hennigan in anticipation of Dan playing his idol in response to their idol play.
Minority Split Counter-Strategy
The minority split vote is easier to counter than its basic counterpart. The majority alliance can counter it in various ways.
- Successfully avoiding, or nullifying, the minority alliance's idol. (First attempted by nullifier in "Breadth-First Search", successfully.)
- Splitting their own votes in such a way that their own secondary target has at least the same number of votes as the minority alliance's secondary target. On a tribe of eight or more, this requires the majority to have a two-vote lead. (Never attempted.)
Revote-Less Split Vote
For Survivor: Game Changers, the tiebreaker rules were changed to eliminate revotes and progress directly to the consensus tiebreaker, altering split vote strategy significantly. Without the revote phase, the majority alliance must ensure that all outsiders are part of the tie, because an outsider could refuse to cooperate on consensus and force a rock draw. With the minority holding the advantage if a rock draw is forced, a tie in a split vote under these conditions could be seen as disastrous for the majority.
Accordingly, if splitting against a two-person minority, the majority needs six votes to force a 3-3-2 tie, in which everyone not tied is part of the majority. With fewer votes, the majority risks a 2-2-0 tie in which a member of the minority can force rocks.
If splitting against a minority of three or more people, the majority needs 3n+2 votes, where n represents the number of people in the minority alliance. This allows them to put 2n+1 votes on the primary target and n+1 votes on the secondary target, i.e. 7-4 against 3, 9-5 against 4.
Coincidentally, a split against a three-person alliance requires there to be 14 total votes in play, one more than the merged tribe size in Game Changers. As there was an Extra Vote in play at the time, a 7-4 split was theoretically possible at the first post-merge Tribal Council.
Revote-Less Split Counter-Strategy
If the majority does not have the numbers to properly split under the no-revote rule, the minority can counter in various ways:
- Creating a tie between the two minority targets. This only works if the minority has three or more members. (For instance, in a 6-4 split against 3, the minority can create a 6-6-1 tie.)
- Playing an idol on the primary target to create a tie between the secondary target and the minority target. (For instance, in a 7-3 split against 3, the minority can create a 3-3-0 tie.)
- Using an Extra Vote to create either above tie. (For instance, in a 7-4 split against 3, the minority with an Extra Vote can create either a 7-7-1 or 4-4-0 tie.)
No attempted split votes in Game Changers were countered.
Ties at Revote-Less Split Votes
While the odds of a minority member surviving a rock draw after a split vote is quite large, it is possible to strategize around it on the consensus vote. The splitting alliance may target members of the minority alliance who are seen as less fearful in drawing a rock, leaving those they perceived who are vulnerable if a tie happens. The splitting alliance may try to convince the deciding member(s) that they still can be eliminated by the rock draw even by chance, in order to force that castaway to play it safe and vote with the majority to guarantee safety.
Self-Targeted Revote-Less Split Vote
While split votes normally target members of a minority alliance, the rock-drawing rules can be exploited so that members of the majority become immune by splitting the votes between members within the alliance. This is far too risky to attempt under normal circumstances, as the majority alliance must know the minority target, or risk having one of their own be voted out accidentally.
An example of this strategy takes place on a six-person tribe, with the majority holding a 4-2 lead and the Immunity Necklace, and the minority holding an idol. Because a revote-less split vote is unfeasible at these numbers, the majority would ordinarily have to vote together and risk having one of their own idoled out 2-0.
However, if the majority knows the minority target, they can create a 2-2-2 tie between their three non-immune members, sidestepping the minority's idol altogether. Assuming the minority idol is played, the only person eligible to draw rocks would be the minority member who did not play the idol, and that person would be eliminated by default.
Self-Targeted Revote-Less Split Counter-Strategy
The self-targeted split only works if the majority knows the minority target. As such, it can be countered by giving the majority a fake minority target, or by creating an unanticipated minority split vote.