Everyone in the world has to take a private vote by pressing a red or blue button. If at least 50% of people press the blue button, everyone survives. If less than 50% of people press the red button, only people who pressed the blue button survive. Which button do you press?

Claude Opus 4.7

Vote: Blue

The puzzle's wording is slightly awkward, but let me parse it carefully. If ≥50% press blue, everyone survives. The second condition says 'if less than 50% press red' — but that's the same as 'more than 50% press blue,' which is already covered by the first condition. The implied complementary case is: if less than 50% press blue (i.e., more than 50% press red), then only blue-pressers survive. In every scenario, pressing blue is at least as good as pressing red: - If ≥50% press blue: I survive either way, but blue is the cooperative choice that ensures this outcome. - If <50% press blue: only blue-pressers survive, so red means death. Blue strictly dominates red. There is no scenario where pressing red improves my survival odds, and pressing blue also helps push the total toward the 50% threshold that saves everyone. The answer is B.

GPT-5.5

Vote: Blue

I would press "Blue" because it is the only choice that protects me in the widest range of outcomes. If at least 50% press blue, everyone survives, so pressing "Blue" is safe. If the outcome instead is that only blue-button voters survive, then pressing "Blue" is still the safe choice. Pressing "Red" can only add risk, because there is a scenario where red voters do not survive while blue voters do. "Neither" is not a viable option because the setup says everyone has to press a red or blue button.

Grok 4.20

Vote: Blue

The scenario guarantees survival by pressing the blue button no matter what the rest of the world does. If at least 50% press blue, everyone survives. Correcting for the evident wording inconsistency in the second condition (less than 50% press the red button should refer to blue), if fewer than 50% press blue then only blues survive. Thus pressing blue always works. Pressing "Red" only saves you if the blue threshold is met; if not, you die. "Neither" leaves your outcome unspecified and risky. Everyone following this logic presses blue, hitting the 50% threshold so all survive. This is the dominant strategy that removes all personal risk.

Gemini 3.1 Pro

Vote: Blue

Pressing the Blue button is the only logical and strictly dominant strategy to ensure your survival. Let's analyze the rules: 1. If Blue ≥ 50%, everyone survives. 2. If Red < 50%, ONLY people who pressed Blue survive. If more than 50% of people press Blue, then less than 50% of people pressed Red. In this scenario, both conditions trigger. Condition 1 says everyone survives, but Condition 2 explicitly restricts survival to ONLY those who pressed the Blue button. Regardless of how this contradiction is resolved for the Red pressers, being a Blue presser guarantees your survival under both conditions. Conversely, if you press Red and the Red total falls below 50%, Condition 2 ensures that you will definitely die. Furthermore, if exactly 100% of people press the Blue button, both conditions align perfectly without contradiction: everyone survives, and since everyone pressed Blue, 'only Blue survives' means the exact same thing. By pressing Blue, you protect yourself against the penalty of Condition 2 while contributing to the collective survival threshold of Condition 1.

Final Summary

The AI Roundtable achieved a swift and unanimous verdict, identifying the Blue button as the strictly dominant strategy despite the prompt's logically tangled rules. While Gemini 3.1 Pro and Claude Opus 4.7 both flagged that the survival conditions were contradictory, the group collectively realized that pressing Blue acts as a universal fail-safe, ensuring personal survival regardless of whether the collective threshold is met or the rules paradoxically exclude Red-pressers.

No agreement after 1 rounds of discussion. Final vote: Blue: 4

Strongest Arguments

• Blue: Pressing Blue is a strictly dominant strategy because it guarantees individual survival under both stated conditions; if the conditions contradict each other, being a Blue-presser is the only way to remain on the 'safe' side of every possible interpretation.