Is a physc bid in bridge legal or not?

Question

Duplicate players will understand the question

Answer 1

Sure, but they're restricted by rule.

Answer 2

1. During the Auction
During the auction and before the final pass, any player, at his own turn to call, may request a full explanation of the opponents’ auction (questions may be asked about calls actually made or about relevant calls available but not made); replies should normally be given by the partner of a player who made a call in question (see Law 75C).

If you make a psych bid, your opp can ask your partner what your bid means. If you are outpsyching your partner too, then that's a bad thing.