I don’t have to know how STAR voting works to know that Gibbard’s 1978 theorem applies. The only game-forms which are straightforward (meaning, one’s best stra

I don’t have to know how STAR voting works to know that Gibbard’s 1978 theorem applies. The only game-forms which are straightforward (meaning, one’s best strategy in what option to choose not depending on how one expects others to choose, or on others’ preferences) are the probability mixtures of “do whatever voter X said to”, “between option A and option B, determine how many voters expressed a preference for A over B and how many for B over A, and if the proportion preferring A is more than p%, pick A, otherwise B”, and “pick outcome C”, with the mixes being any mix of those over any combinations of A,B,C, and X. (So for example, you could flip a coin, and if heads, select a random pair of candidates, and the winner is whichever of the two got more pair wise votes, if tails, select a random voter and go with who they said was their top pick, and if the coin lands on its edge pick Neil deGras Tyson. This would count as “straightforward” because in choosing how you want to vote, it doesn’t matter at all how anyone else is voting.) (Another example is if there are just 2 candidates period. This is also “straightforward”) Outside of such probability mixtures, there can always be situations where your estimate of how other people will vote would influence the most effective way for you to vote in order to best improve your expected outcomes according to your preferences. Outside of such “straightforward” game-forms, there can’t be a function from (your preferences (like, vNM utility, not just a ranking) between the different outcomes) to (a dominant strategy for you). Whatever STAR is, it doesn’t change this fact.