The article Cryptographic Protocols with Everyday Objects by James Heather, Steve Schneider, and Vanessa Teague describes the following unanimity protocol for three players:
Three players want to determine whether they all agree on the point at issue; if they do not all agree, then they will not discover who stands alone against the other two. This is useful in situations where eventual consensus is required, but there is a danger that voters might be unduly influenced by knowledge of the other votes.
Q: The given solution uses playing cards. What is the most natural cryptographic solution of this problem? (Hopefully it will work for more players.)
The secure two-party computation of logical AND from the same article was discussed at Is there a cryptographic solution for this “dating protocol”?.