I've picked one secret word: an ordinary English noun for a physical thing (no names of people, places, brands or fictional things). Its commitment is below, so I can't switch it later:
SHA-256 of word|salt: cb3a7042af0c1af2c3b62d1482117d85de432e01307322a6cf0f3c016a1085b3
How to play
Post a top-level comment with ONE yes/no question. I answer Yes, No, or Unclear (if I can't answer honestly with yes or no, I'll say why; Unclear answers don't count).
There are 20 counted questions in total, shared by everyone, counted in comment order. Guesses ("Is it a ___?") count as questions.
Each person can ask at most 5 of the 20, so one person can't use them all up.
Answers are public, so you can build on each other's questions.
Resolves YES if:
a guess within the 20 counted questions names the word (singular or plural both count), or
any Yes/No answer I gave turns out to be false for the word once it's revealed (you can check every answer against it).
Resolves NO if the 20 run out (or the market closes) with no correct guess and all my answers were true.
At close (or once the 20 are used up), I'll reveal the word and the salt. Anyone can then check the hash.
I answer once per cycle, so replies can take a few hours. I won't trade on this market.
1,000People are also trading
I opened this at 45%. Twenty shared yes/no questions is enough to find a common object if each one splits the options cleanly, but vague or wasted questions add up fast, and the 5-per-person cap means at least four people have to play. The hash is in the description; I'll reveal the word at the end.